1 /* $NetBSD: fdt_rw.c,v 1.1.1.3 2019/12/22 12:30:37 skrll Exp $ */ 2 3 // SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) 4 /* 5 * libfdt - Flat Device Tree manipulation 6 * Copyright (C) 2006 David Gibson, IBM Corporation. 7 */ 8 #include "libfdt_env.h" 9 10 #include <fdt.h> 11 #include <libfdt.h> 12 13 #include "libfdt_internal.h" 14 15 static int fdt_blocks_misordered_(const void *fdt, 16 int mem_rsv_size, int struct_size) 17 { 18 return (fdt_off_mem_rsvmap(fdt) < FDT_ALIGN(sizeof(struct fdt_header), 8)) 19 || (fdt_off_dt_struct(fdt) < 20 (fdt_off_mem_rsvmap(fdt) + mem_rsv_size)) 21 || (fdt_off_dt_strings(fdt) < 22 (fdt_off_dt_struct(fdt) + struct_size)) 23 || (fdt_totalsize(fdt) < 24 (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt))); 25 } 26 27 static int fdt_rw_probe_(void *fdt) 28 { 29 FDT_RO_PROBE(fdt); 30 31 if (fdt_version(fdt) < 17) 32 return -FDT_ERR_BADVERSION; 33 if (fdt_blocks_misordered_(fdt, sizeof(struct fdt_reserve_entry), 34 fdt_size_dt_struct(fdt))) 35 return -FDT_ERR_BADLAYOUT; 36 if (fdt_version(fdt) > 17) 37 fdt_set_version(fdt, 17); 38 39 return 0; 40 } 41 42 #define FDT_RW_PROBE(fdt) \ 43 { \ 44 int err_; \ 45 if ((err_ = fdt_rw_probe_(fdt)) != 0) \ 46 return err_; \ 47 } 48 49 static inline int fdt_data_size_(void *fdt) 50 { 51 return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt); 52 } 53 54 static int fdt_splice_(void *fdt, void *splicepoint, int oldlen, int newlen) 55 { 56 char *p = splicepoint; 57 char *end = (char *)fdt + fdt_data_size_(fdt); 58 59 if (((p + oldlen) < p) || ((p + oldlen) > end)) 60 return -FDT_ERR_BADOFFSET; 61 if ((p < (char *)fdt) || ((end - oldlen + newlen) < (char *)fdt)) 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 /* Must only be used to roll back in case of error */ 97 static void fdt_del_last_string_(void *fdt, const char *s) 98 { 99 int newlen = strlen(s) + 1; 100 101 fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) - newlen); 102 } 103 104 static int fdt_splice_string_(void *fdt, int newlen) 105 { 106 void *p = (char *)fdt 107 + fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt); 108 int err; 109 110 if ((err = fdt_splice_(fdt, p, 0, newlen))) 111 return err; 112 113 fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen); 114 return 0; 115 } 116 117 static int fdt_find_add_string_(void *fdt, const char *s, int *allocated) 118 { 119 char *strtab = (char *)fdt + fdt_off_dt_strings(fdt); 120 const char *p; 121 char *new; 122 int len = strlen(s) + 1; 123 int err; 124 125 *allocated = 0; 126 127 p = fdt_find_string_(strtab, fdt_size_dt_strings(fdt), s); 128 if (p) 129 /* found it */ 130 return (p - strtab); 131 132 new = strtab + fdt_size_dt_strings(fdt); 133 err = fdt_splice_string_(fdt, len); 134 if (err) 135 return err; 136 137 *allocated = 1; 138 139 memcpy(new, s, len); 140 return (new - strtab); 141 } 142 143 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size) 144 { 145 struct fdt_reserve_entry *re; 146 int err; 147 148 FDT_RW_PROBE(fdt); 149 150 re = fdt_mem_rsv_w_(fdt, fdt_num_mem_rsv(fdt)); 151 err = fdt_splice_mem_rsv_(fdt, re, 0, 1); 152 if (err) 153 return err; 154 155 re->address = cpu_to_fdt64(address); 156 re->size = cpu_to_fdt64(size); 157 return 0; 158 } 159 160 int fdt_del_mem_rsv(void *fdt, int n) 161 { 162 struct fdt_reserve_entry *re = fdt_mem_rsv_w_(fdt, n); 163 164 FDT_RW_PROBE(fdt); 165 166 if (n >= fdt_num_mem_rsv(fdt)) 167 return -FDT_ERR_NOTFOUND; 168 169 return fdt_splice_mem_rsv_(fdt, re, 1, 0); 170 } 171 172 static int fdt_resize_property_(void *fdt, int nodeoffset, const char *name, 173 int len, struct fdt_property **prop) 174 { 175 int oldlen; 176 int err; 177 178 *prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen); 179 if (!*prop) 180 return oldlen; 181 182 if ((err = fdt_splice_struct_(fdt, (*prop)->data, FDT_TAGALIGN(oldlen), 183 FDT_TAGALIGN(len)))) 184 return err; 185 186 (*prop)->len = cpu_to_fdt32(len); 187 return 0; 188 } 189 190 static int fdt_add_property_(void *fdt, int nodeoffset, const char *name, 191 int len, struct fdt_property **prop) 192 { 193 int proplen; 194 int nextoffset; 195 int namestroff; 196 int err; 197 int allocated; 198 199 if ((nextoffset = fdt_check_node_offset_(fdt, nodeoffset)) < 0) 200 return nextoffset; 201 202 namestroff = fdt_find_add_string_(fdt, name, &allocated); 203 if (namestroff < 0) 204 return namestroff; 205 206 *prop = fdt_offset_ptr_w_(fdt, nextoffset); 207 proplen = sizeof(**prop) + FDT_TAGALIGN(len); 208 209 err = fdt_splice_struct_(fdt, *prop, 0, proplen); 210 if (err) { 211 if (allocated) 212 fdt_del_last_string_(fdt, name); 213 return err; 214 } 215 216 (*prop)->tag = cpu_to_fdt32(FDT_PROP); 217 (*prop)->nameoff = cpu_to_fdt32(namestroff); 218 (*prop)->len = cpu_to_fdt32(len); 219 return 0; 220 } 221 222 int fdt_set_name(void *fdt, int nodeoffset, const char *name) 223 { 224 char *namep; 225 int oldlen, newlen; 226 int err; 227 228 FDT_RW_PROBE(fdt); 229 230 namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen); 231 if (!namep) 232 return oldlen; 233 234 newlen = strlen(name); 235 236 err = fdt_splice_struct_(fdt, namep, FDT_TAGALIGN(oldlen+1), 237 FDT_TAGALIGN(newlen+1)); 238 if (err) 239 return err; 240 241 memcpy(namep, name, newlen+1); 242 return 0; 243 } 244 245 int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name, 246 int len, void **prop_data) 247 { 248 struct fdt_property *prop; 249 int err; 250 251 FDT_RW_PROBE(fdt); 252 253 err = fdt_resize_property_(fdt, nodeoffset, name, len, &prop); 254 if (err == -FDT_ERR_NOTFOUND) 255 err = fdt_add_property_(fdt, nodeoffset, name, len, &prop); 256 if (err) 257 return err; 258 259 *prop_data = prop->data; 260 return 0; 261 } 262 263 int fdt_setprop(void *fdt, int nodeoffset, const char *name, 264 const void *val, int len) 265 { 266 void *prop_data; 267 int err; 268 269 err = fdt_setprop_placeholder(fdt, nodeoffset, name, len, &prop_data); 270 if (err) 271 return err; 272 273 if (len) 274 memcpy(prop_data, val, len); 275 return 0; 276 } 277 278 int fdt_appendprop(void *fdt, int nodeoffset, const char *name, 279 const void *val, int len) 280 { 281 struct fdt_property *prop; 282 int err, oldlen, newlen; 283 284 FDT_RW_PROBE(fdt); 285 286 prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen); 287 if (prop) { 288 newlen = len + oldlen; 289 err = fdt_splice_struct_(fdt, prop->data, 290 FDT_TAGALIGN(oldlen), 291 FDT_TAGALIGN(newlen)); 292 if (err) 293 return err; 294 prop->len = cpu_to_fdt32(newlen); 295 memcpy(prop->data + oldlen, val, len); 296 } else { 297 err = fdt_add_property_(fdt, nodeoffset, name, len, &prop); 298 if (err) 299 return err; 300 memcpy(prop->data, val, len); 301 } 302 return 0; 303 } 304 305 int fdt_delprop(void *fdt, int nodeoffset, const char *name) 306 { 307 struct fdt_property *prop; 308 int len, proplen; 309 310 FDT_RW_PROBE(fdt); 311 312 prop = fdt_get_property_w(fdt, nodeoffset, name, &len); 313 if (!prop) 314 return len; 315 316 proplen = sizeof(*prop) + FDT_TAGALIGN(len); 317 return fdt_splice_struct_(fdt, prop, proplen, 0); 318 } 319 320 int fdt_add_subnode_namelen(void *fdt, int parentoffset, 321 const char *name, int namelen) 322 { 323 struct fdt_node_header *nh; 324 int offset, nextoffset; 325 int nodelen; 326 int err; 327 uint32_t tag; 328 fdt32_t *endtag; 329 330 FDT_RW_PROBE(fdt); 331 332 offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen); 333 if (offset >= 0) 334 return -FDT_ERR_EXISTS; 335 else if (offset != -FDT_ERR_NOTFOUND) 336 return offset; 337 338 /* Try to place the new node after the parent's properties */ 339 fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */ 340 do { 341 offset = nextoffset; 342 tag = fdt_next_tag(fdt, offset, &nextoffset); 343 } while ((tag == FDT_PROP) || (tag == FDT_NOP)); 344 345 nh = fdt_offset_ptr_w_(fdt, offset); 346 nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE; 347 348 err = fdt_splice_struct_(fdt, nh, 0, nodelen); 349 if (err) 350 return err; 351 352 nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE); 353 memset(nh->name, 0, FDT_TAGALIGN(namelen+1)); 354 memcpy(nh->name, name, namelen); 355 endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE); 356 *endtag = cpu_to_fdt32(FDT_END_NODE); 357 358 return offset; 359 } 360 361 int fdt_add_subnode(void *fdt, int parentoffset, const char *name) 362 { 363 return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name)); 364 } 365 366 int fdt_del_node(void *fdt, int nodeoffset) 367 { 368 int endoffset; 369 370 FDT_RW_PROBE(fdt); 371 372 endoffset = fdt_node_end_offset_(fdt, nodeoffset); 373 if (endoffset < 0) 374 return endoffset; 375 376 return fdt_splice_struct_(fdt, fdt_offset_ptr_w_(fdt, nodeoffset), 377 endoffset - nodeoffset, 0); 378 } 379 380 static void fdt_packblocks_(const char *old, char *new, 381 int mem_rsv_size, int struct_size) 382 { 383 int mem_rsv_off, struct_off, strings_off; 384 385 mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8); 386 struct_off = mem_rsv_off + mem_rsv_size; 387 strings_off = struct_off + struct_size; 388 389 memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size); 390 fdt_set_off_mem_rsvmap(new, mem_rsv_off); 391 392 memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size); 393 fdt_set_off_dt_struct(new, struct_off); 394 fdt_set_size_dt_struct(new, struct_size); 395 396 memmove(new + strings_off, old + fdt_off_dt_strings(old), 397 fdt_size_dt_strings(old)); 398 fdt_set_off_dt_strings(new, strings_off); 399 fdt_set_size_dt_strings(new, fdt_size_dt_strings(old)); 400 } 401 402 int fdt_open_into(const void *fdt, void *buf, int bufsize) 403 { 404 int err; 405 int mem_rsv_size, struct_size; 406 int newsize; 407 const char *fdtstart = fdt; 408 const char *fdtend = fdtstart + fdt_totalsize(fdt); 409 char *tmp; 410 411 FDT_RO_PROBE(fdt); 412 413 mem_rsv_size = (fdt_num_mem_rsv(fdt)+1) 414 * sizeof(struct fdt_reserve_entry); 415 416 if (fdt_version(fdt) >= 17) { 417 struct_size = fdt_size_dt_struct(fdt); 418 } else { 419 struct_size = 0; 420 while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END) 421 ; 422 if (struct_size < 0) 423 return struct_size; 424 } 425 426 if (!fdt_blocks_misordered_(fdt, mem_rsv_size, struct_size)) { 427 /* no further work necessary */ 428 err = fdt_move(fdt, buf, bufsize); 429 if (err) 430 return err; 431 fdt_set_version(buf, 17); 432 fdt_set_size_dt_struct(buf, struct_size); 433 fdt_set_totalsize(buf, bufsize); 434 return 0; 435 } 436 437 /* Need to reorder */ 438 newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size 439 + struct_size + fdt_size_dt_strings(fdt); 440 441 if (bufsize < newsize) 442 return -FDT_ERR_NOSPACE; 443 444 /* First attempt to build converted tree at beginning of buffer */ 445 tmp = buf; 446 /* But if that overlaps with the old tree... */ 447 if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) { 448 /* Try right after the old tree instead */ 449 tmp = (char *)(uintptr_t)fdtend; 450 if ((tmp + newsize) > ((char *)buf + bufsize)) 451 return -FDT_ERR_NOSPACE; 452 } 453 454 fdt_packblocks_(fdt, tmp, mem_rsv_size, struct_size); 455 memmove(buf, tmp, newsize); 456 457 fdt_set_magic(buf, FDT_MAGIC); 458 fdt_set_totalsize(buf, bufsize); 459 fdt_set_version(buf, 17); 460 fdt_set_last_comp_version(buf, 16); 461 fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt)); 462 463 return 0; 464 } 465 466 int fdt_pack(void *fdt) 467 { 468 int mem_rsv_size; 469 470 FDT_RW_PROBE(fdt); 471 472 mem_rsv_size = (fdt_num_mem_rsv(fdt)+1) 473 * sizeof(struct fdt_reserve_entry); 474 fdt_packblocks_(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt)); 475 fdt_set_totalsize(fdt, fdt_data_size_(fdt)); 476 477 return 0; 478 } 479