lib/libfdt/fdt_rw.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_blocks_misordered(const void *fdt,
  18                               int mem_rsv_size, int struct_size)
  19 {
  20         return (fdt_off_mem_rsvmap(fdt) < FDT_ALIGN(sizeof(struct fdt_header), 8))
  21                 || (fdt_off_dt_struct(fdt) <
  22                     (fdt_off_mem_rsvmap(fdt) + mem_rsv_size))
  23                 || (fdt_off_dt_strings(fdt) <
  24                     (fdt_off_dt_struct(fdt) + struct_size))
  25                 || (fdt_totalsize(fdt) <
  26                     (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
  27 }
  28
  29 static int _fdt_rw_check_header(void *fdt)
  30 {
  31         FDT_CHECK_HEADER(fdt);
  32
  33         if (fdt_version(fdt) < 17)
  34                 return -FDT_ERR_BADVERSION;
  35         if (_fdt_blocks_misordered(fdt, sizeof(struct fdt_reserve_entry),
  36                                    fdt_size_dt_struct(fdt)))
  37                 return -FDT_ERR_BADLAYOUT;
  38         if (fdt_version(fdt) > 17)
  39                 fdt_set_version(fdt, 17);
  40
  41         return 0;
  42 }
  43
  44 #define FDT_RW_CHECK_HEADER(fdt) \
  45         { \
  46                 int __err; \
  47                 if ((__err = _fdt_rw_check_header(fdt)) != 0) \
  48                         return __err; \
  49         }
  50
  51 static inline int _fdt_data_size(void *fdt)
  52 {
  53         return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
  54 }
  55
  56 static int _fdt_splice(void *fdt, void *splicepoint, int oldlen, int newlen)
  57 {
  58         char *p = splicepoint;
  59         char *end = (char *)fdt + _fdt_data_size(fdt);
  60
  61         if (((p + oldlen) < p) || ((p + oldlen) > end))
  62                 return -FDT_ERR_BADOFFSET;
  63         if ((p < (char *)fdt) || ((end - oldlen + newlen) < (char *)fdt))
  64                 return -FDT_ERR_BADOFFSET;
  65         if ((end - oldlen + newlen) > ((char *)fdt + fdt_totalsize(fdt)))
  66                 return -FDT_ERR_NOSPACE;
  67         memmove(p + newlen, p + oldlen, end - p - oldlen);
  68         return 0;
  69 }
  70
  71 static int _fdt_splice_mem_rsv(void *fdt, struct fdt_reserve_entry *p,
  72                                int oldn, int newn)
  73 {
  74         int delta = (newn - oldn) * sizeof(*p);
  75         int err;
  76         err = _fdt_splice(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
  77         if (err)
  78                 return err;
  79         fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
  80         fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
  81         return 0;
  82 }
  83
  84 static int _fdt_splice_struct(void *fdt, void *p,
  85                               int oldlen, int newlen)
  86 {
  87         int delta = newlen - oldlen;
  88         int err;
  89
  90         if ((err = _fdt_splice(fdt, p, oldlen, newlen)))
  91                 return err;
  92
  93         fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
  94         fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
  95         return 0;
  96 }
  97
  98 static int _fdt_splice_string(void *fdt, int newlen)
  99 {
 100         void *p = (char *)fdt
 101                 + fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
 102         int err;
 103
 104         if ((err = _fdt_splice(fdt, p, 0, newlen)))
 105                 return err;
 106
 107         fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
 108         return 0;
 109 }
 110
 111 static int _fdt_find_add_string(void *fdt, const char *s)
 112 {
 113         char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
 114         const char *p;
 115         char *new;
 116         int len = strlen(s) + 1;
 117         int err;
 118
 119         p = _fdt_find_string(strtab, fdt_size_dt_strings(fdt), s);
 120         if (p)
 121                 /* found it */
 122                 return (p - strtab);
 123
 124         new = strtab + fdt_size_dt_strings(fdt);
 125         err = _fdt_splice_string(fdt, len);
 126         if (err)
 127                 return err;
 128
 129         memcpy(new, s, len);
 130         return (new - strtab);
 131 }
 132
 133 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
 134 {
 135         struct fdt_reserve_entry *re;
 136         int err;
 137
 138         FDT_RW_CHECK_HEADER(fdt);
 139
 140         re = _fdt_mem_rsv_w(fdt, fdt_num_mem_rsv(fdt));
 141         err = _fdt_splice_mem_rsv(fdt, re, 0, 1);
 142         if (err)
 143                 return err;
 144
 145         re->address = cpu_to_fdt64(address);
 146         re->size = cpu_to_fdt64(size);
 147         return 0;
 148 }
 149
 150 int fdt_del_mem_rsv(void *fdt, int n)
 151 {
 152         struct fdt_reserve_entry *re = _fdt_mem_rsv_w(fdt, n);
 153
 154         FDT_RW_CHECK_HEADER(fdt);
 155
 156         if (n >= fdt_num_mem_rsv(fdt))
 157                 return -FDT_ERR_NOTFOUND;
 158
 159         return _fdt_splice_mem_rsv(fdt, re, 1, 0);
 160 }
 161
 162 static int _fdt_resize_property(void *fdt, int nodeoffset, const char *name,
 163                                 int len, struct fdt_property **prop)
 164 {
 165         int oldlen;
 166         int err;
 167
 168         *prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
 169         if (!*prop)
 170                 return oldlen;
 171
 172         if ((err = _fdt_splice_struct(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
 173                                       FDT_TAGALIGN(len))))
 174                 return err;
 175
 176         (*prop)->len = cpu_to_fdt32(len);
 177         return 0;
 178 }
 179
 180 static int _fdt_add_property(void *fdt, int nodeoffset, const char *name,
 181                              int len, struct fdt_property **prop)
 182 {
 183         int proplen;
 184         int nextoffset;
 185         int namestroff;
 186         int err;
 187
 188         if ((nextoffset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
 189                 return nextoffset;
 190
 191         namestroff = _fdt_find_add_string(fdt, name);
 192         if (namestroff < 0)
 193                 return namestroff;
 194
 195         *prop = _fdt_offset_ptr_w(fdt, nextoffset);
 196         proplen = sizeof(**prop) + FDT_TAGALIGN(len);
 197
 198         err = _fdt_splice_struct(fdt, *prop, 0, proplen);
 199         if (err)
 200                 return err;
 201
 202         (*prop)->tag = cpu_to_fdt32(FDT_PROP);
 203         (*prop)->nameoff = cpu_to_fdt32(namestroff);
 204         (*prop)->len = cpu_to_fdt32(len);
 205         return 0;
 206 }
 207
 208 int fdt_set_name(void *fdt, int nodeoffset, const char *name)
 209 {
 210         char *namep;
 211         int oldlen, newlen;
 212         int err;
 213
 214         FDT_RW_CHECK_HEADER(fdt);
 215
 216         namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
 217         if (!namep)
 218                 return oldlen;
 219
 220         newlen = strlen(name);
 221
 222         err = _fdt_splice_struct(fdt, namep, FDT_TAGALIGN(oldlen+1),
 223                                  FDT_TAGALIGN(newlen+1));
 224         if (err)
 225                 return err;
 226
 227         memcpy(namep, name, newlen+1);
 228         return 0;
 229 }
 230
 231 int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
 232                             int len, void **prop_data)
 233 {
 234         struct fdt_property *prop;
 235         int err;
 236
 237         FDT_RW_CHECK_HEADER(fdt);
 238
 239         err = _fdt_resize_property(fdt, nodeoffset, name, len, &prop);
 240         if (err == -FDT_ERR_NOTFOUND)
 241                 err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
 242         if (err)
 243                 return err;
 244
 245         *prop_data = prop->data;
 246         return 0;
 247 }
 248
 249 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
 250                 const void *val, int len)
 251 {
 252         void *prop_data;
 253         int err;
 254
 255         err = fdt_setprop_placeholder(fdt, nodeoffset, name, len, &prop_data);
 256         if (err)
 257                 return err;
 258
 259         if (len)
 260                 memcpy(prop_data, val, len);
 261         return 0;
 262 }
 263
 264 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
 265                    const void *val, int len)
 266 {
 267         struct fdt_property *prop;
 268         int err, oldlen, newlen;
 269
 270         FDT_RW_CHECK_HEADER(fdt);
 271
 272         prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
 273         if (prop) {
 274                 newlen = len + oldlen;
 275                 err = _fdt_splice_struct(fdt, prop->data,
 276                                          FDT_TAGALIGN(oldlen),
 277                                          FDT_TAGALIGN(newlen));
 278                 if (err)
 279                         return err;
 280                 prop->len = cpu_to_fdt32(newlen);
 281                 memcpy(prop->data + oldlen, val, len);
 282         } else {
 283                 err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
 284                 if (err)
 285                         return err;
 286                 memcpy(prop->data, val, len);
 287         }
 288         return 0;
 289 }
 290
 291 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
 292 {
 293         struct fdt_property *prop;
 294         int len, proplen;
 295
 296         FDT_RW_CHECK_HEADER(fdt);
 297
 298         prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
 299         if (!prop)
 300                 return len;
 301
 302         proplen = sizeof(*prop) + FDT_TAGALIGN(len);
 303         return _fdt_splice_struct(fdt, prop, proplen, 0);
 304 }
 305
 306 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
 307                             const char *name, int namelen)
 308 {
 309         struct fdt_node_header *nh;
 310         int offset, nextoffset;
 311         int nodelen;
 312         int err;
 313         uint32_t tag;
 314         fdt32_t *endtag;
 315
 316         FDT_RW_CHECK_HEADER(fdt);
 317
 318         offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
 319         if (offset >= 0)
 320                 return -FDT_ERR_EXISTS;
 321         else if (offset != -FDT_ERR_NOTFOUND)
 322                 return offset;
 323
 324         /* Try to place the new node after the parent's properties */
 325         fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
 326         do {
 327                 offset = nextoffset;
 328                 tag = fdt_next_tag(fdt, offset, &nextoffset);
 329         } while ((tag == FDT_PROP) || (tag == FDT_NOP));
 330
 331         nh = _fdt_offset_ptr_w(fdt, offset);
 332         nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
 333
 334         err = _fdt_splice_struct(fdt, nh, 0, nodelen);
 335         if (err)
 336                 return err;
 337
 338         nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
 339         memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
 340         memcpy(nh->name, name, namelen);
 341         endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
 342         *endtag = cpu_to_fdt32(FDT_END_NODE);
 343
 344         return offset;
 345 }
 346
 347 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
 348 {
 349         return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
 350 }
 351
 352 int fdt_del_node(void *fdt, int nodeoffset)
 353 {
 354         int endoffset;
 355
 356         FDT_RW_CHECK_HEADER(fdt);
 357
 358         endoffset = _fdt_node_end_offset(fdt, nodeoffset);
 359         if (endoffset < 0)
 360                 return endoffset;
 361
 362         return _fdt_splice_struct(fdt, _fdt_offset_ptr_w(fdt, nodeoffset),
 363                                   endoffset - nodeoffset, 0);
 364 }
 365
 366 static void _fdt_packblocks(const char *old, char *new,
 367                             int mem_rsv_size, int struct_size)
 368 {
 369         int mem_rsv_off, struct_off, strings_off;
 370
 371         mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
 372         struct_off = mem_rsv_off + mem_rsv_size;
 373         strings_off = struct_off + struct_size;
 374
 375         memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
 376         fdt_set_off_mem_rsvmap(new, mem_rsv_off);
 377
 378         memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
 379         fdt_set_off_dt_struct(new, struct_off);
 380         fdt_set_size_dt_struct(new, struct_size);
 381
 382         memmove(new + strings_off, old + fdt_off_dt_strings(old),
 383                 fdt_size_dt_strings(old));
 384         fdt_set_off_dt_strings(new, strings_off);
 385         fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
 386 }
 387
 388 int fdt_open_into(const void *fdt, void *buf, int bufsize)
 389 {
 390         int err;
 391         int mem_rsv_size, struct_size;
 392         int newsize;
 393         const char *fdtstart = fdt;
 394         const char *fdtend = fdtstart + fdt_totalsize(fdt);
 395         char *tmp;
 396
 397         FDT_CHECK_HEADER(fdt);
 398
 399         mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
 400                 * sizeof(struct fdt_reserve_entry);
 401
 402         if (fdt_version(fdt) >= 17) {
 403                 struct_size = fdt_size_dt_struct(fdt);
 404         } else {
 405                 struct_size = 0;
 406                 while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
 407                         ;
 408                 if (struct_size < 0)
 409                         return struct_size;
 410         }
 411
 412         if (!_fdt_blocks_misordered(fdt, mem_rsv_size, struct_size)) {
 413                 /* no further work necessary */
 414                 err = fdt_move(fdt, buf, bufsize);
 415                 if (err)
 416                         return err;
 417                 fdt_set_version(buf, 17);
 418                 fdt_set_size_dt_struct(buf, struct_size);
 419                 fdt_set_totalsize(buf, bufsize);
 420                 return 0;
 421         }
 422
 423         /* Need to reorder */
 424         newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
 425                 + struct_size + fdt_size_dt_strings(fdt);
 426
 427         if (bufsize < newsize)
 428                 return -FDT_ERR_NOSPACE;
 429
 430         /* First attempt to build converted tree at beginning of buffer */
 431         tmp = buf;
 432         /* But if that overlaps with the old tree... */
 433         if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
 434                 /* Try right after the old tree instead */
 435                 tmp = (char *)(uintptr_t)fdtend;
 436                 if ((tmp + newsize) > ((char *)buf + bufsize))
 437                         return -FDT_ERR_NOSPACE;
 438         }
 439
 440         _fdt_packblocks(fdt, tmp, mem_rsv_size, struct_size);
 441         memmove(buf, tmp, newsize);
 442
 443         fdt_set_magic(buf, FDT_MAGIC);
 444         fdt_set_totalsize(buf, bufsize);
 445         fdt_set_version(buf, 17);
 446         fdt_set_last_comp_version(buf, 16);
 447         fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
 448
 449         return 0;
 450 }
 451
 452 int fdt_pack(void *fdt)
 453 {
 454         int mem_rsv_size;
 455
 456         FDT_RW_CHECK_HEADER(fdt);
 457
 458         mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
 459                 * sizeof(struct fdt_reserve_entry);
 460         _fdt_packblocks(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
 461         fdt_set_totalsize(fdt, _fdt_data_size(fdt));
 462
 463         return 0;
 464 }
 465
 466 int fdt_remove_unused_strings(const void *old, void *new)
 467 {
 468         const struct fdt_property *old_prop;
 469         struct fdt_property *new_prop;
 470         int size = fdt_totalsize(old);
 471         int next_offset, offset;
 472         const char *str;
 473         int ret;
 474         int tag = FDT_PROP;
 475
 476         /* Make a copy and remove the strings */
 477         memcpy(new, old, size);
 478         fdt_set_size_dt_strings(new, 0);
 479
 480         /* Add every property name back into the new string table */
 481         for (offset = 0; tag != FDT_END; offset = next_offset) {
 482                 tag = fdt_next_tag(old, offset, &next_offset);
 483                 if (tag != FDT_PROP)
 484                         continue;
 485                 old_prop = fdt_get_property_by_offset(old, offset, NULL);
 486                 new_prop = (struct fdt_property *)(unsigned long)
 487                         fdt_get_property_by_offset(new, offset, NULL);
 488                 str = fdt_string(old, fdt32_to_cpu(old_prop->nameoff));
 489                 ret = _fdt_find_add_string(new, str);
 490                 if (ret < 0)
 491                         return ret;
 492                 new_prop->nameoff = cpu_to_fdt32(ret);
 493         }
 494
 495         return 0;
 496 }