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