arch/powerpc/boot/flatdevtree.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License as published by
   4  * the Free Software Foundation; either version 2 of the License, or
   5  * (at your option) any later version.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  15  *
  16  * Copyright Pantelis Antoniou 2006
  17  * Copyright (C) IBM Corporation 2006
  18  *
  19  * Authors: Pantelis Antoniou <pantelis@embeddedalley.com>
  20  *          Hollis Blanchard <hollisb@us.ibm.com>
  21  *          Mark A. Greer <mgreer@mvista.com>
  22  *          Paul Mackerras <paulus@samba.org>
  23  */
  24
  25 #include <string.h>
  26 #include <stddef.h>
  27 #include "flatdevtree.h"
  28 #include "flatdevtree_env.h"
  29
  30 #define _ALIGN(x, al)   (((x) + (al) - 1) & ~((al) - 1))
  31
  32 static char *ft_root_node(struct ft_cxt *cxt)
  33 {
  34         return cxt->rgn[FT_STRUCT].start;
  35 }
  36
  37 /* Routines for keeping node ptrs returned by ft_find_device current */
  38 /* First entry not used b/c it would return 0 and be taken as NULL/error */
  39 static void *ft_get_phandle(struct ft_cxt *cxt, char *node)
  40 {
  41         unsigned int i;
  42
  43         if (!node)
  44                 return NULL;
  45
  46         for (i = 1; i < cxt->nodes_used; i++)   /* already there? */
  47                 if (cxt->node_tbl[i] == node)
  48                         return (void *)i;
  49
  50         if (cxt->nodes_used < cxt->node_max) {
  51                 cxt->node_tbl[cxt->nodes_used] = node;
  52                 return (void *)cxt->nodes_used++;
  53         }
  54
  55         return NULL;
  56 }
  57
  58 static char *ft_node_ph2node(struct ft_cxt *cxt, const void *phandle)
  59 {
  60         unsigned int i = (unsigned int)phandle;
  61
  62         if (i < cxt->nodes_used)
  63                 return cxt->node_tbl[i];
  64         return NULL;
  65 }
  66
  67 static void ft_node_update_before(struct ft_cxt *cxt, char *addr, int shift)
  68 {
  69         unsigned int i;
  70
  71         if (shift == 0)
  72                 return;
  73
  74         for (i = 1; i < cxt->nodes_used; i++)
  75                 if (cxt->node_tbl[i] < addr)
  76                         cxt->node_tbl[i] += shift;
  77 }
  78
  79 static void ft_node_update_after(struct ft_cxt *cxt, char *addr, int shift)
  80 {
  81         unsigned int i;
  82
  83         if (shift == 0)
  84                 return;
  85
  86         for (i = 1; i < cxt->nodes_used; i++)
  87                 if (cxt->node_tbl[i] >= addr)
  88                         cxt->node_tbl[i] += shift;
  89 }
  90
  91 /* Struct used to return info from ft_next() */
  92 struct ft_atom {
  93         u32 tag;
  94         const char *name;
  95         void *data;
  96         u32 size;
  97 };
  98
  99 /* Set ptrs to current one's info; return addr of next one */
 100 static char *ft_next(struct ft_cxt *cxt, char *p, struct ft_atom *ret)
 101 {
 102         u32 sz;
 103
 104         if (p >= cxt->rgn[FT_STRUCT].start + cxt->rgn[FT_STRUCT].size)
 105                 return NULL;
 106
 107         ret->tag = be32_to_cpu(*(u32 *) p);
 108         p += 4;
 109
 110         switch (ret->tag) {     /* Tag */
 111         case OF_DT_BEGIN_NODE:
 112                 ret->name = p;
 113                 ret->data = (void *)(p - 4);    /* start of node */
 114                 p += _ALIGN(strlen(p) + 1, 4);
 115                 break;
 116         case OF_DT_PROP:
 117                 ret->size = sz = be32_to_cpu(*(u32 *) p);
 118                 ret->name = cxt->str_anchor + be32_to_cpu(*(u32 *) (p + 4));
 119                 ret->data = (void *)(p + 8);
 120                 p += 8 + _ALIGN(sz, 4);
 121                 break;
 122         case OF_DT_END_NODE:
 123         case OF_DT_NOP:
 124                 break;
 125         case OF_DT_END:
 126         default:
 127                 p = NULL;
 128                 break;
 129         }
 130
 131         return p;
 132 }
 133
 134 #define HDR_SIZE        _ALIGN(sizeof(struct boot_param_header), 8)
 135 #define EXPAND_INCR     1024    /* alloc this much extra when expanding */
 136
 137 /* Copy the tree to a newly-allocated region and put things in order */
 138 static int ft_reorder(struct ft_cxt *cxt, int nextra)
 139 {
 140         unsigned long tot;
 141         enum ft_rgn_id r;
 142         char *p, *pend;
 143         int stroff;
 144
 145         tot = HDR_SIZE + EXPAND_INCR;
 146         for (r = FT_RSVMAP; r <= FT_STRINGS; ++r)
 147                 tot += cxt->rgn[r].size;
 148         if (nextra > 0)
 149                 tot += nextra;
 150         tot = _ALIGN(tot, 8);
 151
 152         if (!cxt->realloc)
 153                 return 0;
 154         p = cxt->realloc(NULL, tot);
 155         if (!p)
 156                 return 0;
 157
 158         memcpy(p, cxt->bph, sizeof(struct boot_param_header));
 159         /* offsets get fixed up later */
 160
 161         cxt->bph = (struct boot_param_header *)p;
 162         cxt->max_size = tot;
 163         pend = p + tot;
 164         p += HDR_SIZE;
 165
 166         memcpy(p, cxt->rgn[FT_RSVMAP].start, cxt->rgn[FT_RSVMAP].size);
 167         cxt->rgn[FT_RSVMAP].start = p;
 168         p += cxt->rgn[FT_RSVMAP].size;
 169
 170         memcpy(p, cxt->rgn[FT_STRUCT].start, cxt->rgn[FT_STRUCT].size);
 171         ft_node_update_after(cxt, cxt->rgn[FT_STRUCT].start,
 172                         p - cxt->rgn[FT_STRUCT].start);
 173         cxt->p += p - cxt->rgn[FT_STRUCT].start;
 174         cxt->rgn[FT_STRUCT].start = p;
 175
 176         p = pend - cxt->rgn[FT_STRINGS].size;
 177         memcpy(p, cxt->rgn[FT_STRINGS].start, cxt->rgn[FT_STRINGS].size);
 178         stroff = cxt->str_anchor - cxt->rgn[FT_STRINGS].start;
 179         cxt->rgn[FT_STRINGS].start = p;
 180         cxt->str_anchor = p + stroff;
 181
 182         cxt->isordered = 1;
 183         return 1;
 184 }
 185
 186 static inline char *prev_end(struct ft_cxt *cxt, enum ft_rgn_id r)
 187 {
 188         if (r > FT_RSVMAP)
 189                 return cxt->rgn[r - 1].start + cxt->rgn[r - 1].size;
 190         return (char *)cxt->bph + HDR_SIZE;
 191 }
 192
 193 static inline char *next_start(struct ft_cxt *cxt, enum ft_rgn_id r)
 194 {
 195         if (r < FT_STRINGS)
 196                 return cxt->rgn[r + 1].start;
 197         return (char *)cxt->bph + cxt->max_size;
 198 }
 199
 200 /*
 201  * See if we can expand region rgn by nextra bytes by using up
 202  * free space after or before the region.
 203  */
 204 static int ft_shuffle(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
 205                 int nextra)
 206 {
 207         char *p = *pp;
 208         char *rgn_start, *rgn_end;
 209
 210         rgn_start = cxt->rgn[rgn].start;
 211         rgn_end = rgn_start + cxt->rgn[rgn].size;
 212         if (nextra <= 0 || rgn_end + nextra <= next_start(cxt, rgn)) {
 213                 /* move following stuff */
 214                 if (p < rgn_end) {
 215                         if (nextra < 0)
 216                                 memmove(p, p - nextra, rgn_end - p + nextra);
 217                         else
 218                                 memmove(p + nextra, p, rgn_end - p);
 219                         if (rgn == FT_STRUCT)
 220                                 ft_node_update_after(cxt, p, nextra);
 221                 }
 222                 cxt->rgn[rgn].size += nextra;
 223                 if (rgn == FT_STRINGS)
 224                         /* assumes strings only added at beginning */
 225                         cxt->str_anchor += nextra;
 226                 return 1;
 227         }
 228         if (prev_end(cxt, rgn) <= rgn_start - nextra) {
 229                 /* move preceding stuff */
 230                 if (p > rgn_start) {
 231                         memmove(rgn_start - nextra, rgn_start, p - rgn_start);
 232                         if (rgn == FT_STRUCT)
 233                                 ft_node_update_before(cxt, p, -nextra);
 234                 }
 235                 *pp -= nextra;
 236                 cxt->rgn[rgn].start -= nextra;
 237                 cxt->rgn[rgn].size += nextra;
 238                 return 1;
 239         }
 240         return 0;
 241 }
 242
 243 static int ft_make_space(struct ft_cxt *cxt, char **pp, enum ft_rgn_id rgn,
 244                          int nextra)
 245 {
 246         unsigned long size, ssize, tot;
 247         char *str, *next;
 248         enum ft_rgn_id r;
 249
 250         if (!cxt->isordered) {
 251                 unsigned long rgn_off = *pp - cxt->rgn[rgn].start;
 252
 253                 if (!ft_reorder(cxt, nextra))
 254                         return 0;
 255
 256                 *pp = cxt->rgn[rgn].start + rgn_off;
 257         }
 258         if (ft_shuffle(cxt, pp, rgn, nextra))
 259                 return 1;
 260
 261         /* See if there is space after the strings section */
 262         ssize = cxt->rgn[FT_STRINGS].size;
 263         if (cxt->rgn[FT_STRINGS].start + ssize
 264                         < (char *)cxt->bph + cxt->max_size) {
 265                 /* move strings up as far as possible */
 266                 str = (char *)cxt->bph + cxt->max_size - ssize;
 267                 cxt->str_anchor += str - cxt->rgn[FT_STRINGS].start;
 268                 memmove(str, cxt->rgn[FT_STRINGS].start, ssize);
 269                 cxt->rgn[FT_STRINGS].start = str;
 270                 /* enough space now? */
 271                 if (rgn >= FT_STRUCT && ft_shuffle(cxt, pp, rgn, nextra))
 272                         return 1;
 273         }
 274
 275         /* how much total free space is there following this region? */
 276         tot = 0;
 277         for (r = rgn; r < FT_STRINGS; ++r) {
 278                 char *r_end = cxt->rgn[r].start + cxt->rgn[r].size;
 279                 tot += next_start(cxt, rgn) - r_end;
 280         }
 281
 282         /* cast is to shut gcc up; we know nextra >= 0 */
 283         if (tot < (unsigned int)nextra) {
 284                 /* have to reallocate */
 285                 char *newp, *new_start;
 286                 int shift;
 287
 288                 if (!cxt->realloc)
 289                         return 0;
 290                 size = _ALIGN(cxt->max_size + (nextra - tot) + EXPAND_INCR, 8);
 291                 newp = cxt->realloc(cxt->bph, size);
 292                 if (!newp)
 293                         return 0;
 294                 cxt->max_size = size;
 295                 shift = newp - (char *)cxt->bph;
 296
 297                 if (shift) { /* realloc can return same addr */
 298                         cxt->bph = (struct boot_param_header *)newp;
 299                         ft_node_update_after(cxt, cxt->rgn[FT_STRUCT].start,
 300                                         shift);
 301                         for (r = FT_RSVMAP; r <= FT_STRINGS; ++r) {
 302                                 new_start = cxt->rgn[r].start + shift;
 303                                 cxt->rgn[r].start = new_start;
 304                         }
 305                         *pp += shift;
 306                         cxt->str_anchor += shift;
 307                 }
 308
 309                 /* move strings up to the end */
 310                 str = newp + size - ssize;
 311                 cxt->str_anchor += str - cxt->rgn[FT_STRINGS].start;
 312                 memmove(str, cxt->rgn[FT_STRINGS].start, ssize);
 313                 cxt->rgn[FT_STRINGS].start = str;
 314
 315                 if (ft_shuffle(cxt, pp, rgn, nextra))
 316                         return 1;
 317         }
 318
 319         /* must be FT_RSVMAP and we need to move FT_STRUCT up */
 320         if (rgn == FT_RSVMAP) {
 321                 next = cxt->rgn[FT_RSVMAP].start + cxt->rgn[FT_RSVMAP].size
 322                         + nextra;
 323                 ssize = cxt->rgn[FT_STRUCT].size;
 324                 if (next + ssize >= cxt->rgn[FT_STRINGS].start)
 325                         return 0;       /* "can't happen" */
 326                 memmove(next, cxt->rgn[FT_STRUCT].start, ssize);
 327                 ft_node_update_after(cxt, cxt->rgn[FT_STRUCT].start, nextra);
 328                 cxt->rgn[FT_STRUCT].start = next;
 329
 330                 if (ft_shuffle(cxt, pp, rgn, nextra))
 331                         return 1;
 332         }
 333
 334         return 0;               /* "can't happen" */
 335 }
 336
 337 static void ft_put_word(struct ft_cxt *cxt, u32 v)
 338 {
 339         *(u32 *) cxt->p = cpu_to_be32(v);
 340         cxt->p += 4;
 341 }
 342
 343 static void ft_put_bin(struct ft_cxt *cxt, const void *data, unsigned int sz)
 344 {
 345         unsigned long sza = _ALIGN(sz, 4);
 346
 347         /* zero out the alignment gap if necessary */
 348         if (sz < sza)
 349                 *(u32 *) (cxt->p + sza - 4) = 0;
 350
 351         /* copy in the data */
 352         memcpy(cxt->p, data, sz);
 353
 354         cxt->p += sza;
 355 }
 356
 357 int ft_begin_node(struct ft_cxt *cxt, const char *name)
 358 {
 359         unsigned long nlen = strlen(name) + 1;
 360         unsigned long len = 8 + _ALIGN(nlen, 4);
 361
 362         if (!ft_make_space(cxt, &cxt->p, FT_STRUCT, len))
 363                 return -1;
 364         ft_put_word(cxt, OF_DT_BEGIN_NODE);
 365         ft_put_bin(cxt, name, strlen(name) + 1);
 366         return 0;
 367 }
 368
 369 void ft_end_node(struct ft_cxt *cxt)
 370 {
 371         ft_put_word(cxt, OF_DT_END_NODE);
 372 }
 373
 374 void ft_nop(struct ft_cxt *cxt)
 375 {
 376         if (ft_make_space(cxt, &cxt->p, FT_STRUCT, 4))
 377                 ft_put_word(cxt, OF_DT_NOP);
 378 }
 379
 380 #define NO_STRING       0x7fffffff
 381
 382 static int lookup_string(struct ft_cxt *cxt, const char *name)
 383 {
 384         char *p, *end;
 385
 386         p = cxt->rgn[FT_STRINGS].start;
 387         end = p + cxt->rgn[FT_STRINGS].size;
 388         while (p < end) {
 389                 if (strcmp(p, (char *)name) == 0)
 390                         return p - cxt->str_anchor;
 391                 p += strlen(p) + 1;
 392         }
 393
 394         return NO_STRING;
 395 }
 396
 397 /* lookup string and insert if not found */
 398 static int map_string(struct ft_cxt *cxt, const char *name)
 399 {
 400         int off;
 401         char *p;
 402
 403         off = lookup_string(cxt, name);
 404         if (off != NO_STRING)
 405                 return off;
 406         p = cxt->rgn[FT_STRINGS].start;
 407         if (!ft_make_space(cxt, &p, FT_STRINGS, strlen(name) + 1))
 408                 return NO_STRING;
 409         strcpy(p, name);
 410         return p - cxt->str_anchor;
 411 }
 412
 413 int ft_prop(struct ft_cxt *cxt, const char *name, const void *data,
 414                 unsigned int sz)
 415 {
 416         int off, len;
 417
 418         off = map_string(cxt, name);
 419         if (off == NO_STRING)
 420                 return -1;
 421
 422         len = 12 + _ALIGN(sz, 4);
 423         if (!ft_make_space(cxt, &cxt->p, FT_STRUCT, len))
 424                 return -1;
 425
 426         ft_put_word(cxt, OF_DT_PROP);
 427         ft_put_word(cxt, sz);
 428         ft_put_word(cxt, off);
 429         ft_put_bin(cxt, data, sz);
 430         return 0;
 431 }
 432
 433 int ft_prop_str(struct ft_cxt *cxt, const char *name, const char *str)
 434 {
 435         return ft_prop(cxt, name, str, strlen(str) + 1);
 436 }
 437
 438 int ft_prop_int(struct ft_cxt *cxt, const char *name, unsigned int val)
 439 {
 440         u32 v = cpu_to_be32((u32) val);
 441
 442         return ft_prop(cxt, name, &v, 4);
 443 }
 444
 445 /* Calculate the size of the reserved map */
 446 static unsigned long rsvmap_size(struct ft_cxt *cxt)
 447 {
 448         struct ft_reserve *res;
 449
 450         res = (struct ft_reserve *)cxt->rgn[FT_RSVMAP].start;
 451         while (res->start || res->len)
 452                 ++res;
 453         return (char *)(res + 1) - cxt->rgn[FT_RSVMAP].start;
 454 }
 455
 456 /* Calculate the size of the struct region by stepping through it */
 457 static unsigned long struct_size(struct ft_cxt *cxt)
 458 {
 459         char *p = cxt->rgn[FT_STRUCT].start;
 460         char *next;
 461         struct ft_atom atom;
 462
 463         /* make check in ft_next happy */
 464         if (cxt->rgn[FT_STRUCT].size == 0)
 465                 cxt->rgn[FT_STRUCT].size = 0xfffffffful - (unsigned long)p;
 466
 467         while ((next = ft_next(cxt, p, &atom)) != NULL)
 468                 p = next;
 469         return p + 4 - cxt->rgn[FT_STRUCT].start;
 470 }
 471
 472 /* add `adj' on to all string offset values in the struct area */
 473 static void adjust_string_offsets(struct ft_cxt *cxt, int adj)
 474 {
 475         char *p = cxt->rgn[FT_STRUCT].start;
 476         char *next;
 477         struct ft_atom atom;
 478         int off;
 479
 480         while ((next = ft_next(cxt, p, &atom)) != NULL) {
 481                 if (atom.tag == OF_DT_PROP) {
 482                         off = be32_to_cpu(*(u32 *) (p + 8));
 483                         *(u32 *) (p + 8) = cpu_to_be32(off + adj);
 484                 }
 485                 p = next;
 486         }
 487 }
 488
 489 /* start construction of the flat OF tree from scratch */
 490 void ft_begin(struct ft_cxt *cxt, void *blob, unsigned int max_size,
 491                 void *(*realloc_fn) (void *, unsigned long))
 492 {
 493         struct boot_param_header *bph = blob;
 494         char *p;
 495         struct ft_reserve *pres;
 496
 497         /* clear the cxt */
 498         memset(cxt, 0, sizeof(*cxt));
 499
 500         cxt->bph = bph;
 501         cxt->max_size = max_size;
 502         cxt->realloc = realloc_fn;
 503         cxt->isordered = 1;
 504
 505         /* zero everything in the header area */
 506         memset(bph, 0, sizeof(*bph));
 507
 508         bph->magic = cpu_to_be32(OF_DT_HEADER);
 509         bph->version = cpu_to_be32(0x10);
 510         bph->last_comp_version = cpu_to_be32(0x10);
 511
 512         /* start pointers */
 513         cxt->rgn[FT_RSVMAP].start = p = blob + HDR_SIZE;
 514         cxt->rgn[FT_RSVMAP].size = sizeof(struct ft_reserve);
 515         pres = (struct ft_reserve *)p;
 516         cxt->rgn[FT_STRUCT].start = p += sizeof(struct ft_reserve);
 517         cxt->rgn[FT_STRUCT].size = 4;
 518         cxt->rgn[FT_STRINGS].start = blob + max_size;
 519         cxt->rgn[FT_STRINGS].size = 0;
 520
 521         /* init rsvmap and struct */
 522         pres->start = 0;
 523         pres->len = 0;
 524         *(u32 *) p = cpu_to_be32(OF_DT_END);
 525
 526         cxt->str_anchor = blob;
 527 }
 528
 529 /* open up an existing blob to be examined or modified */
 530 int ft_open(struct ft_cxt *cxt, void *blob, unsigned int max_size,
 531                 unsigned int max_find_device,
 532                 void *(*realloc_fn) (void *, unsigned long))
 533 {
 534         struct boot_param_header *bph = blob;
 535
 536         /* can't cope with version < 16 */
 537         if (be32_to_cpu(bph->version) < 16)
 538                 return -1;
 539
 540         /* clear the cxt */
 541         memset(cxt, 0, sizeof(*cxt));
 542
 543         /* alloc node_tbl to track node ptrs returned by ft_find_device */
 544         ++max_find_device;
 545         cxt->node_tbl = realloc_fn(NULL, max_find_device * sizeof(char *));
 546         if (!cxt->node_tbl)
 547                 return -1;
 548         memset(cxt->node_tbl, 0, max_find_device * sizeof(char *));
 549         cxt->node_max = max_find_device;
 550         cxt->nodes_used = 1;    /* don't use idx 0 b/c looks like NULL */
 551
 552         cxt->bph = bph;
 553         cxt->max_size = max_size;
 554         cxt->realloc = realloc_fn;
 555
 556         cxt->rgn[FT_RSVMAP].start = blob + be32_to_cpu(bph->off_mem_rsvmap);
 557         cxt->rgn[FT_RSVMAP].size = rsvmap_size(cxt);
 558         cxt->rgn[FT_STRUCT].start = blob + be32_to_cpu(bph->off_dt_struct);
 559         cxt->rgn[FT_STRUCT].size = struct_size(cxt);
 560         cxt->rgn[FT_STRINGS].start = blob + be32_to_cpu(bph->off_dt_strings);
 561         cxt->rgn[FT_STRINGS].size = be32_to_cpu(bph->dt_strings_size);
 562
 563         cxt->p = cxt->rgn[FT_STRUCT].start;
 564         cxt->str_anchor = cxt->rgn[FT_STRINGS].start;
 565
 566         return 0;
 567 }
 568
 569 /* add a reserver physical area to the rsvmap */
 570 int ft_add_rsvmap(struct ft_cxt *cxt, u64 physaddr, u64 size)
 571 {
 572         char *p;
 573         struct ft_reserve *pres;
 574
 575         p = cxt->rgn[FT_RSVMAP].start + cxt->rgn[FT_RSVMAP].size
 576                 - sizeof(struct ft_reserve);
 577         if (!ft_make_space(cxt, &p, FT_RSVMAP, sizeof(struct ft_reserve)))
 578                 return -1;
 579
 580         pres = (struct ft_reserve *)p;
 581         pres->start = cpu_to_be64(physaddr);
 582         pres->len = cpu_to_be64(size);
 583
 584         return 0;
 585 }
 586
 587 void ft_begin_tree(struct ft_cxt *cxt)
 588 {
 589         cxt->p = ft_root_node(cxt);
 590 }
 591
 592 void ft_end_tree(struct ft_cxt *cxt)
 593 {
 594         struct boot_param_header *bph = cxt->bph;
 595         char *p, *oldstr, *str, *endp;
 596         unsigned long ssize;
 597         int adj;
 598
 599         if (!cxt->isordered)
 600                 return;         /* we haven't touched anything */
 601
 602         /* adjust string offsets */
 603         oldstr = cxt->rgn[FT_STRINGS].start;
 604         adj = cxt->str_anchor - oldstr;
 605         if (adj)
 606                 adjust_string_offsets(cxt, adj);
 607
 608         /* make strings end on 8-byte boundary */
 609         ssize = cxt->rgn[FT_STRINGS].size;
 610         endp = (char *)_ALIGN((unsigned long)cxt->rgn[FT_STRUCT].start
 611                         + cxt->rgn[FT_STRUCT].size + ssize, 8);
 612         str = endp - ssize;
 613
 614         /* move strings down to end of structs */
 615         memmove(str, oldstr, ssize);
 616         cxt->str_anchor = str;
 617         cxt->rgn[FT_STRINGS].start = str;
 618
 619         /* fill in header fields */
 620         p = (char *)bph;
 621         bph->totalsize = cpu_to_be32(endp - p);
 622         bph->off_mem_rsvmap = cpu_to_be32(cxt->rgn[FT_RSVMAP].start - p);
 623         bph->off_dt_struct = cpu_to_be32(cxt->rgn[FT_STRUCT].start - p);
 624         bph->off_dt_strings = cpu_to_be32(cxt->rgn[FT_STRINGS].start - p);
 625         bph->dt_strings_size = cpu_to_be32(ssize);
 626 }
 627
 628 void *ft_find_device(struct ft_cxt *cxt, const char *srch_path)
 629 {
 630         char *node;
 631
 632         /* require absolute path */
 633         if (srch_path[0] != '/')
 634                 return NULL;
 635         node = ft_find_descendent(cxt, ft_root_node(cxt), srch_path);
 636         return ft_get_phandle(cxt, node);
 637 }
 638
 639 void *ft_find_device_rel(struct ft_cxt *cxt, const void *top,
 640                          const char *srch_path)
 641 {
 642         char *node;
 643
 644         node = ft_node_ph2node(cxt, top);
 645         if (node == NULL)
 646                 return NULL;
 647
 648         node = ft_find_descendent(cxt, node, srch_path);
 649         return ft_get_phandle(cxt, node);
 650 }
 651
 652 void *ft_find_descendent(struct ft_cxt *cxt, void *top, const char *srch_path)
 653 {
 654         struct ft_atom atom;
 655         char *p;
 656         const char *cp, *q;
 657         int cl;
 658         int depth = -1;
 659         int dmatch = 0;
 660         const char *path_comp[FT_MAX_DEPTH];
 661
 662         cp = srch_path;
 663         cl = 0;
 664         p = top;
 665
 666         while ((p = ft_next(cxt, p, &atom)) != NULL) {
 667                 switch (atom.tag) {
 668                 case OF_DT_BEGIN_NODE:
 669                         ++depth;
 670                         if (depth != dmatch)
 671                                 break;
 672                         cxt->genealogy[depth] = atom.data;
 673                         cxt->genealogy[depth + 1] = NULL;
 674                         if (depth && !(strncmp(atom.name, cp, cl) == 0
 675                                         && (atom.name[cl] == '/'
 676                                                 || atom.name[cl] == '\0'
 677                                                 || atom.name[cl] == '@')))
 678                                 break;
 679                         path_comp[dmatch] = cp;
 680                         /* it matches so far, advance to next path component */
 681                         cp += cl;
 682                         /* skip slashes */
 683                         while (*cp == '/')
 684                                 ++cp;
 685                         /* we're done if this is the end of the string */
 686                         if (*cp == 0)
 687                                 return atom.data;
 688                         /* look for end of this component */
 689                         q = strchr(cp, '/');
 690                         if (q)
 691                                 cl = q - cp;
 692                         else
 693                                 cl = strlen(cp);
 694                         ++dmatch;
 695                         break;
 696                 case OF_DT_END_NODE:
 697                         if (depth == 0)
 698                                 return NULL;
 699                         if (dmatch > depth) {
 700                                 --dmatch;
 701                                 cl = cp - path_comp[dmatch] - 1;
 702                                 cp = path_comp[dmatch];
 703                                 while (cl > 0 && cp[cl - 1] == '/')
 704                                         --cl;
 705                         }
 706                         --depth;
 707                         break;
 708                 }
 709         }
 710         return NULL;
 711 }
 712
 713 void *__ft_get_parent(struct ft_cxt *cxt, void *node)
 714 {
 715         int d;
 716         struct ft_atom atom;
 717         char *p;
 718
 719         for (d = 0; cxt->genealogy[d] != NULL; ++d)
 720                 if (cxt->genealogy[d] == node)
 721                         return d > 0 ? cxt->genealogy[d - 1] : NULL;
 722
 723         /* have to do it the hard way... */
 724         p = ft_root_node(cxt);
 725         d = 0;
 726         while ((p = ft_next(cxt, p, &atom)) != NULL) {
 727                 switch (atom.tag) {
 728                 case OF_DT_BEGIN_NODE:
 729                         cxt->genealogy[d] = atom.data;
 730                         if (node == atom.data) {
 731                                 /* found it */
 732                                 cxt->genealogy[d + 1] = NULL;
 733                                 return d > 0 ? cxt->genealogy[d - 1] : NULL;
 734                         }
 735                         ++d;
 736                         break;
 737                 case OF_DT_END_NODE:
 738                         --d;
 739                         break;
 740                 }
 741         }
 742         return NULL;
 743 }
 744
 745 void *ft_get_parent(struct ft_cxt *cxt, const void *phandle)
 746 {
 747         void *node = ft_node_ph2node(cxt, phandle);
 748         if (node == NULL)
 749                 return NULL;
 750
 751         node = __ft_get_parent(cxt, node);
 752         return ft_get_phandle(cxt, node);
 753 }
 754
 755 static const void *__ft_get_prop(struct ft_cxt *cxt, void *node,
 756                                  const char *propname, unsigned int *len)
 757 {
 758         struct ft_atom atom;
 759         int depth = 0;
 760
 761         while ((node = ft_next(cxt, node, &atom)) != NULL) {
 762                 switch (atom.tag) {
 763                 case OF_DT_BEGIN_NODE:
 764                         ++depth;
 765                         break;
 766
 767                 case OF_DT_PROP:
 768                         if (depth != 1 || strcmp(atom.name, propname))
 769                                 break;
 770
 771                         if (len)
 772                                 *len = atom.size;
 773
 774                         return atom.data;
 775
 776                 case OF_DT_END_NODE:
 777                         if (--depth <= 0)
 778                                 return NULL;
 779                 }
 780         }
 781
 782         return NULL;
 783 }
 784
 785 int ft_get_prop(struct ft_cxt *cxt, const void *phandle, const char *propname,
 786                 void *buf, const unsigned int buflen)
 787 {
 788         const void *data;
 789         unsigned int size;
 790
 791         void *node = ft_node_ph2node(cxt, phandle);
 792         if (!node)
 793                 return -1;
 794
 795         data = __ft_get_prop(cxt, node, propname, &size);
 796         if (data) {
 797                 unsigned int clipped_size = min(size, buflen);
 798                 memcpy(buf, data, clipped_size);
 799                 return size;
 800         }
 801
 802         return -1;
 803 }
 804
 805 void *__ft_find_node_by_prop_value(struct ft_cxt *cxt, void *prev,
 806                                    const char *propname, const char *propval,
 807                                    unsigned int proplen)
 808 {
 809         struct ft_atom atom;
 810         char *p = ft_root_node(cxt);
 811         char *next;
 812         int past_prev = prev ? 0 : 1;
 813         int depth = -1;
 814
 815         while ((next = ft_next(cxt, p, &atom)) != NULL) {
 816                 const void *data;
 817                 unsigned int size;
 818
 819                 switch (atom.tag) {
 820                 case OF_DT_BEGIN_NODE:
 821                         depth++;
 822
 823                         if (prev == p) {
 824                                 past_prev = 1;
 825                                 break;
 826                         }
 827
 828                         if (!past_prev || depth < 1)
 829                                 break;
 830
 831                         data = __ft_get_prop(cxt, p, propname, &size);
 832                         if (!data || size != proplen)
 833                                 break;
 834                         if (memcmp(data, propval, size))
 835                                 break;
 836
 837                         return p;
 838
 839                 case OF_DT_END_NODE:
 840                         if (depth-- == 0)
 841                                 return NULL;
 842
 843                         break;
 844                 }
 845
 846                 p = next;
 847         }
 848
 849         return NULL;
 850 }
 851
 852 void *ft_find_node_by_prop_value(struct ft_cxt *cxt, const void *prev,
 853                                  const char *propname, const char *propval,
 854                                  int proplen)
 855 {
 856         void *node = NULL;
 857
 858         if (prev) {
 859                 node = ft_node_ph2node(cxt, prev);
 860
 861                 if (!node)
 862                         return NULL;
 863         }
 864
 865         node = __ft_find_node_by_prop_value(cxt, node, propname,
 866                                             propval, proplen);
 867         return ft_get_phandle(cxt, node);
 868 }
 869
 870 int ft_set_prop(struct ft_cxt *cxt, const void *phandle, const char *propname,
 871                 const void *buf, const unsigned int buflen)
 872 {
 873         struct ft_atom atom;
 874         void *node;
 875         char *p, *next;
 876         int nextra;
 877
 878         node = ft_node_ph2node(cxt, phandle);
 879         if (node == NULL)
 880                 return -1;
 881
 882         next = ft_next(cxt, node, &atom);
 883         if (atom.tag != OF_DT_BEGIN_NODE)
 884                 /* phandle didn't point to a node */
 885                 return -1;
 886         p = next;
 887
 888         while ((next = ft_next(cxt, p, &atom)) != NULL) {
 889                 switch (atom.tag) {
 890                 case OF_DT_BEGIN_NODE: /* properties must go before subnodes */
 891                 case OF_DT_END_NODE:
 892                         /* haven't found the property, insert here */
 893                         cxt->p = p;
 894                         return ft_prop(cxt, propname, buf, buflen);
 895                 case OF_DT_PROP:
 896                         if (strcmp(atom.name, propname))
 897                                 break;
 898                         /* found an existing property, overwrite it */
 899                         nextra = _ALIGN(buflen, 4) - _ALIGN(atom.size, 4);
 900                         cxt->p = atom.data;
 901                         if (nextra && !ft_make_space(cxt, &cxt->p, FT_STRUCT,
 902                                                 nextra))
 903                                 return -1;
 904                         *(u32 *) (cxt->p - 8) = cpu_to_be32(buflen);
 905                         ft_put_bin(cxt, buf, buflen);
 906                         return 0;
 907                 }
 908                 p = next;
 909         }
 910         return -1;
 911 }
 912
 913 int ft_del_prop(struct ft_cxt *cxt, const void *phandle, const char *propname)
 914 {
 915         struct ft_atom atom;
 916         void *node;
 917         char *p, *next;
 918         int size;
 919
 920         node = ft_node_ph2node(cxt, phandle);
 921         if (node == NULL)
 922                 return -1;
 923
 924         p = node;
 925         while ((next = ft_next(cxt, p, &atom)) != NULL) {
 926                 switch (atom.tag) {
 927                 case OF_DT_BEGIN_NODE:
 928                 case OF_DT_END_NODE:
 929                         return -1;
 930                 case OF_DT_PROP:
 931                         if (strcmp(atom.name, propname))
 932                                 break;
 933                         /* found the property, remove it */
 934                         size = 12 + -_ALIGN(atom.size, 4);
 935                         cxt->p = p;
 936                         if (!ft_make_space(cxt, &cxt->p, FT_STRUCT, -size))
 937                                 return -1;
 938                         return 0;
 939                 }
 940                 p = next;
 941         }
 942         return -1;
 943 }
 944
 945 void *ft_create_node(struct ft_cxt *cxt, const void *parent, const char *name)
 946 {
 947         struct ft_atom atom;
 948         char *p, *next;
 949         int depth = 0;
 950
 951         if (parent) {
 952                 p = ft_node_ph2node(cxt, parent);
 953                 if (!p)
 954                         return NULL;
 955         } else {
 956                 p = ft_root_node(cxt);
 957         }
 958
 959         while ((next = ft_next(cxt, p, &atom)) != NULL) {
 960                 switch (atom.tag) {
 961                 case OF_DT_BEGIN_NODE:
 962                         ++depth;
 963                         if (depth == 1 && strcmp(atom.name, name) == 0)
 964                                 /* duplicate node name, return error */
 965                                 return NULL;
 966                         break;
 967                 case OF_DT_END_NODE:
 968                         --depth;
 969                         if (depth > 0)
 970                                 break;
 971                         /* end of node, insert here */
 972                         cxt->p = p;
 973                         ft_begin_node(cxt, name);
 974                         ft_end_node(cxt);
 975                         return p;
 976                 }
 977                 p = next;
 978         }
 979         return NULL;
 980 }