1// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) 2/* 3 * libfdt - Flat Device Tree manipulation 4 * Copyright (C) 2006 David Gibson, IBM Corporation. 5 */ 6#include "libfdt_env.h" 7 8#include <fdt.h> 9#include <libfdt.h> 10 11#include "libfdt_internal.h" 12 13static int fdt_sw_probe_(void *fdt) 14{ 15 if (fdt_chk_basic()) { 16 if (fdt_magic(fdt) == FDT_MAGIC) 17 return -FDT_ERR_BADSTATE; 18 else if (fdt_magic(fdt) != FDT_SW_MAGIC) 19 return -FDT_ERR_BADMAGIC; 20 } 21 22 return 0; 23} 24 25#define FDT_SW_PROBE(fdt) \ 26 { \ 27 int err; \ 28 if (fdt_chk_basic() && (err = fdt_sw_probe_(fdt)) != 0) \ 29 return err; \ 30 } 31 32/* 'memrsv' state: Initial state after fdt_create() 33 * 34 * Allowed functions: 35 * fdt_add_reservmap_entry() 36 * fdt_finish_reservemap() [moves to 'struct' state] 37 */ 38static int fdt_sw_probe_memrsv_(void *fdt) 39{ 40 int err = fdt_sw_probe_(fdt); 41 if (err) 42 return err; 43 44 if (fdt_chk_extra() && fdt_off_dt_strings(fdt) != 0) 45 return -FDT_ERR_BADSTATE; 46 return 0; 47} 48 49#define FDT_SW_PROBE_MEMRSV(fdt) \ 50 { \ 51 int err; \ 52 if (fdt_chk_extra() && (err = fdt_sw_probe_memrsv_(fdt)) != 0) \ 53 return err; \ 54 } 55 56/* 'struct' state: Enter this state after fdt_finish_reservemap() 57 * 58 * Allowed functions: 59 * fdt_begin_node() 60 * fdt_end_node() 61 * fdt_property*() 62 * fdt_finish() [moves to 'complete' state] 63 */ 64static int fdt_sw_probe_struct_(void *fdt) 65{ 66 int err; 67 68 if (!fdt_chk_extra()) 69 return 0; 70 err = fdt_sw_probe_(fdt); 71 if (err) 72 return err; 73 74 if (fdt_off_dt_strings(fdt) != fdt_totalsize(fdt)) 75 return -FDT_ERR_BADSTATE; 76 return 0; 77} 78 79#define FDT_SW_PROBE_STRUCT(fdt) \ 80 { \ 81 int err; \ 82 if (fdt_chk_extra() && (err = fdt_sw_probe_struct_(fdt)) != 0) \ 83 return err; \ 84 } 85 86static inline uint32_t sw_flags(void *fdt) 87{ 88 /* assert: (fdt_magic(fdt) == FDT_SW_MAGIC) */ 89 return fdt_last_comp_version(fdt); 90} 91 92/* 'complete' state: Enter this state after fdt_finish() 93 * 94 * Allowed functions: none 95 */ 96 97static void *fdt_grab_space_(void *fdt, size_t len) 98{ 99 unsigned int offset = fdt_size_dt_struct(fdt); 100 unsigned int spaceleft; 101 102 spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt) 103 - fdt_size_dt_strings(fdt); 104 105 if ((offset + len < offset) || (offset + len > spaceleft)) 106 return NULL; 107 108 fdt_set_size_dt_struct(fdt, offset + len); 109 return fdt_offset_ptr_w_(fdt, offset); 110} 111 112int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags) 113{ 114 const int hdrsize = FDT_ALIGN(sizeof(struct fdt_header), 115 sizeof(struct fdt_reserve_entry)); 116 void *fdt = buf; 117 118 if (bufsize < hdrsize) 119 return -FDT_ERR_NOSPACE; 120 121 if (flags & ~FDT_CREATE_FLAGS_ALL) 122 return -FDT_ERR_BADFLAGS; 123 124 memset(buf, 0, bufsize); 125 126 /* 127 * magic and last_comp_version keep intermediate state during the fdt 128 * creation process, which is replaced with the proper FDT format by 129 * fdt_finish(). 130 * 131 * flags should be accessed with sw_flags(). 132 */ 133 fdt_set_magic(fdt, FDT_SW_MAGIC); 134 fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION); 135 fdt_set_last_comp_version(fdt, flags); 136 137 fdt_set_totalsize(fdt, bufsize); 138 139 fdt_set_off_mem_rsvmap(fdt, hdrsize); 140 fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt)); 141 fdt_set_off_dt_strings(fdt, 0); 142 143 return 0; 144} 145 146int fdt_create(void *buf, int bufsize) 147{ 148 return fdt_create_with_flags(buf, bufsize, 0); 149} 150 151int fdt_resize(void *fdt, void *buf, int bufsize) 152{ 153 size_t headsize, tailsize; 154 char *oldtail, *newtail; 155 156 FDT_SW_PROBE(fdt); 157 158 if (bufsize < 0) 159 return -FDT_ERR_NOSPACE; 160 161 headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); 162 tailsize = fdt_size_dt_strings(fdt); 163 164 if (fdt_chk_extra() && (headsize + tailsize) > fdt_totalsize(fdt)) 165 return -FDT_ERR_INTERNAL; 166 167 if ((headsize + tailsize) > (unsigned)bufsize) 168 return -FDT_ERR_NOSPACE; 169 170 oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize; 171 newtail = (char *)buf + bufsize - tailsize; 172 173 /* Two cases to avoid clobbering data if the old and new 174 * buffers partially overlap */ 175 if (buf <= fdt) { 176 memmove(buf, fdt, headsize); 177 memmove(newtail, oldtail, tailsize); 178 } else { 179 memmove(newtail, oldtail, tailsize); 180 memmove(buf, fdt, headsize); 181 } 182 183 fdt_set_totalsize(buf, bufsize); 184 if (fdt_off_dt_strings(buf)) 185 fdt_set_off_dt_strings(buf, bufsize); 186 187 return 0; 188} 189 190int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size) 191{ 192 struct fdt_reserve_entry *re; 193 int offset; 194 195 FDT_SW_PROBE_MEMRSV(fdt); 196 197 offset = fdt_off_dt_struct(fdt); 198 if ((offset + sizeof(*re)) > fdt_totalsize(fdt)) 199 return -FDT_ERR_NOSPACE; 200 201 re = (struct fdt_reserve_entry *)((char *)fdt + offset); 202 re->address = cpu_to_fdt64(addr); 203 re->size = cpu_to_fdt64(size); 204 205 fdt_set_off_dt_struct(fdt, offset + sizeof(*re)); 206 207 return 0; 208} 209 210int fdt_finish_reservemap(void *fdt) 211{ 212 int err = fdt_add_reservemap_entry(fdt, 0, 0); 213 214 if (err) 215 return err; 216 217 fdt_set_off_dt_strings(fdt, fdt_totalsize(fdt)); 218 return 0; 219} 220 221int fdt_begin_node(void *fdt, const char *name) 222{ 223 struct fdt_node_header *nh; 224 int namelen; 225 226 FDT_SW_PROBE_STRUCT(fdt); 227 228 namelen = strlen(name) + 1; 229 nh = fdt_grab_space_(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen)); 230 if (! nh) 231 return -FDT_ERR_NOSPACE; 232 233 nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE); 234 memcpy(nh->name, name, namelen); 235 return 0; 236} 237 238int fdt_end_node(void *fdt) 239{ 240 fdt32_t *en; 241 242 FDT_SW_PROBE_STRUCT(fdt); 243 244 en = fdt_grab_space_(fdt, FDT_TAGSIZE); 245 if (! en) 246 return -FDT_ERR_NOSPACE; 247 248 *en = cpu_to_fdt32(FDT_END_NODE); 249 return 0; 250} 251 252static int fdt_add_string_(void *fdt, const char *s) 253{ 254 char *strtab = (char *)fdt + fdt_totalsize(fdt); 255 unsigned int strtabsize = fdt_size_dt_strings(fdt); 256 unsigned int len = strlen(s) + 1; 257 unsigned int struct_top, offset; 258 259 offset = strtabsize + len; 260 struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); 261 if (fdt_totalsize(fdt) - offset < struct_top) 262 return 0; /* no more room :( */ 263 264 memcpy(strtab - offset, s, len); 265 fdt_set_size_dt_strings(fdt, strtabsize + len); 266 return -offset; 267} 268 269/* Must only be used to roll back in case of error */ 270static void fdt_del_last_string_(void *fdt, const char *s) 271{ 272 int strtabsize = fdt_size_dt_strings(fdt); 273 int len = strlen(s) + 1; 274 275 fdt_set_size_dt_strings(fdt, strtabsize - len); 276} 277 278static int fdt_find_add_string_(void *fdt, const char *s, int *allocated) 279{ 280 char *strtab = (char *)fdt + fdt_totalsize(fdt); 281 int strtabsize = fdt_size_dt_strings(fdt); 282 const char *p; 283 284 *allocated = 0; 285 286 p = fdt_find_string_(strtab - strtabsize, strtabsize, s); 287 if (p) 288 return p - strtab; 289 290 *allocated = 1; 291 292 return fdt_add_string_(fdt, s); 293} 294 295int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp) 296{ 297 struct fdt_property *prop; 298 int nameoff; 299 int allocated; 300 301 FDT_SW_PROBE_STRUCT(fdt); 302 303 /* String de-duplication can be slow, _NO_NAME_DEDUP skips it */ 304 if (sw_flags(fdt) & FDT_CREATE_FLAG_NO_NAME_DEDUP) { 305 allocated = 1; 306 nameoff = fdt_add_string_(fdt, name); 307 } else { 308 nameoff = fdt_find_add_string_(fdt, name, &allocated); 309 } 310 if (nameoff == 0) 311 return -FDT_ERR_NOSPACE; 312 313 prop = fdt_grab_space_(fdt, sizeof(*prop) + FDT_TAGALIGN(len)); 314 if (! prop) { 315 if (allocated) 316 fdt_del_last_string_(fdt, name); 317 return -FDT_ERR_NOSPACE; 318 } 319 320 prop->tag = cpu_to_fdt32(FDT_PROP); 321 prop->nameoff = cpu_to_fdt32(nameoff); 322 prop->len = cpu_to_fdt32(len); 323 *valp = prop->data; 324 return 0; 325} 326 327int fdt_property(void *fdt, const char *name, const void *val, int len) 328{ 329 void *ptr; 330 int ret; 331 332 ret = fdt_property_placeholder(fdt, name, len, &ptr); 333 if (ret) 334 return ret; 335 memcpy(ptr, val, len); 336 return 0; 337} 338 339int fdt_finish(void *fdt) 340{ 341 char *p = (char *)fdt; 342 fdt32_t *end; 343 int oldstroffset, newstroffset; 344 uint32_t tag; 345 int offset, nextoffset; 346 347 FDT_SW_PROBE_STRUCT(fdt); 348 349 /* Add terminator */ 350 end = fdt_grab_space_(fdt, sizeof(*end)); 351 if (! end) 352 return -FDT_ERR_NOSPACE; 353 *end = cpu_to_fdt32(FDT_END); 354 355 /* Relocate the string table */ 356 oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt); 357 newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); 358 memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt)); 359 fdt_set_off_dt_strings(fdt, newstroffset); 360 361 /* Walk the structure, correcting string offsets */ 362 offset = 0; 363 while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) { 364 if (tag == FDT_PROP) { 365 struct fdt_property *prop = 366 fdt_offset_ptr_w_(fdt, offset); 367 int nameoff; 368 369 nameoff = fdt32_to_cpu(prop->nameoff); 370 nameoff += fdt_size_dt_strings(fdt); 371 prop->nameoff = cpu_to_fdt32(nameoff); 372 } 373 offset = nextoffset; 374 } 375 if (nextoffset < 0) 376 return nextoffset; 377 378 /* Finally, adjust the header */ 379 fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt)); 380 381 /* And fix up fields that were keeping intermediate state. */ 382 fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION); 383 fdt_set_magic(fdt, FDT_MAGIC); 384 385 return 0; 386} 387