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 char *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         char *ret;
 362
 363         if (!ft_make_space(cxt, &cxt->p, FT_STRUCT, len))
 364                 return NULL;
 365
 366         ret = cxt->p;
 367
 368         ft_put_word(cxt, OF_DT_BEGIN_NODE);
 369         ft_put_bin(cxt, name, strlen(name) + 1);
 370
 371         return ret;
 372 }
 373
 374 void ft_end_node(struct ft_cxt *cxt)
 375 {
 376         ft_put_word(cxt, OF_DT_END_NODE);
 377 }
 378
 379 void ft_nop(struct ft_cxt *cxt)
 380 {
 381         if (ft_make_space(cxt, &cxt->p, FT_STRUCT, 4))
 382                 ft_put_word(cxt, OF_DT_NOP);
 383 }
 384
 385 #define NO_STRING       0x7fffffff
 386
 387 static int lookup_string(struct ft_cxt *cxt, const char *name)
 388 {
 389         char *p, *end;
 390
 391         p = cxt->rgn[FT_STRINGS].start;
 392         end = p + cxt->rgn[FT_STRINGS].size;
 393         while (p < end) {
 394                 if (strcmp(p, (char *)name) == 0)
 395                         return p - cxt->str_anchor;
 396                 p += strlen(p) + 1;
 397         }
 398
 399         return NO_STRING;
 400 }
 401
 402 /* lookup string and insert if not found */
 403 static int map_string(struct ft_cxt *cxt, const char *name)
 404 {
 405         int off;
 406         char *p;
 407
 408         off = lookup_string(cxt, name);
 409         if (off != NO_STRING)
 410                 return off;
 411         p = cxt->rgn[FT_STRINGS].start;
 412         if (!ft_make_space(cxt, &p, FT_STRINGS, strlen(name) + 1))
 413                 return NO_STRING;
 414         strcpy(p, name);
 415         return p - cxt->str_anchor;
 416 }
 417
 418 int ft_prop(struct ft_cxt *cxt, const char *name, const void *data,
 419                 unsigned int sz)
 420 {
 421         int off, len;
 422
 423         off = map_string(cxt, name);
 424         if (off == NO_STRING)
 425                 return -1;
 426
 427         len = 12 + _ALIGN(sz, 4);
 428         if (!ft_make_space(cxt, &cxt->p, FT_STRUCT, len))
 429                 return -1;
 430
 431         ft_put_word(cxt, OF_DT_PROP);
 432         ft_put_word(cxt, sz);
 433         ft_put_word(cxt, off);
 434         ft_put_bin(cxt, data, sz);
 435         return 0;
 436 }
 437
 438 int ft_prop_str(struct ft_cxt *cxt, const char *name, const char *str)
 439 {
 440         return ft_prop(cxt, name, str, strlen(str) + 1);
 441 }
 442
 443 int ft_prop_int(struct ft_cxt *cxt, const char *name, unsigned int val)
 444 {
 445         u32 v = cpu_to_be32((u32) val);
 446
 447         return ft_prop(cxt, name, &v, 4);
 448 }
 449
 450 /* Calculate the size of the reserved map */
 451 static unsigned long rsvmap_size(struct ft_cxt *cxt)
 452 {
 453         struct ft_reserve *res;
 454
 455         res = (struct ft_reserve *)cxt->rgn[FT_RSVMAP].start;
 456         while (res->start || res->len)
 457                 ++res;
 458         return (char *)(res + 1) - cxt->rgn[FT_RSVMAP].start;
 459 }
 460
 461 /* Calculate the size of the struct region by stepping through it */
 462 static unsigned long struct_size(struct ft_cxt *cxt)
 463 {
 464         char *p = cxt->rgn[FT_STRUCT].start;
 465         char *next;
 466         struct ft_atom atom;
 467
 468         /* make check in ft_next happy */
 469         if (cxt->rgn[FT_STRUCT].size == 0)
 470                 cxt->rgn[FT_STRUCT].size = 0xfffffffful - (unsigned long)p;
 471
 472         while ((next = ft_next(cxt, p, &atom)) != NULL)
 473                 p = next;
 474         return p + 4 - cxt->rgn[FT_STRUCT].start;
 475 }
 476
 477 /* add `adj' on to all string offset values in the struct area */
 478 static void adjust_string_offsets(struct ft_cxt *cxt, int adj)
 479 {
 480         char *p = cxt->rgn[FT_STRUCT].start;
 481         char *next;
 482         struct ft_atom atom;
 483         int off;
 484
 485         while ((next = ft_next(cxt, p, &atom)) != NULL) {
 486                 if (atom.tag == OF_DT_PROP) {
 487                         off = be32_to_cpu(*(u32 *) (p + 8));
 488                         *(u32 *) (p + 8) = cpu_to_be32(off + adj);
 489                 }
 490                 p = next;
 491         }
 492 }
 493
 494 /* start construction of the flat OF tree from scratch */
 495 void ft_begin(struct ft_cxt *cxt, void *blob, unsigned int max_size,
 496                 void *(*realloc_fn) (void *, unsigned long))
 497 {
 498         struct boot_param_header *bph = blob;
 499         char *p;
 500         struct ft_reserve *pres;
 501
 502         /* clear the cxt */
 503         memset(cxt, 0, sizeof(*cxt));
 504
 505         cxt->bph = bph;
 506         cxt->max_size = max_size;
 507         cxt->realloc = realloc_fn;
 508         cxt->isordered = 1;
 509
 510         /* zero everything in the header area */
 511         memset(bph, 0, sizeof(*bph));
 512
 513         bph->magic = cpu_to_be32(OF_DT_HEADER);
 514         bph->version = cpu_to_be32(0x10);
 515         bph->last_comp_version = cpu_to_be32(0x10);
 516
 517         /* start pointers */
 518         cxt->rgn[FT_RSVMAP].start = p = blob + HDR_SIZE;
 519         cxt->rgn[FT_RSVMAP].size = sizeof(struct ft_reserve);
 520         pres = (struct ft_reserve *)p;
 521         cxt->rgn[FT_STRUCT].start = p += sizeof(struct ft_reserve);
 522         cxt->rgn[FT_STRUCT].size = 4;
 523         cxt->rgn[FT_STRINGS].start = blob + max_size;
 524         cxt->rgn[FT_STRINGS].size = 0;
 525
 526         /* init rsvmap and struct */
 527         pres->start = 0;
 528         pres->len = 0;
 529         *(u32 *) p = cpu_to_be32(OF_DT_END);
 530
 531         cxt->str_anchor = blob;
 532 }
 533
 534 /* open up an existing blob to be examined or modified */
 535 int ft_open(struct ft_cxt *cxt, void *blob, unsigned int max_size,
 536                 unsigned int max_find_device,
 537                 void *(*realloc_fn) (void *, unsigned long))
 538 {
 539         struct boot_param_header *bph = blob;
 540
 541         /* can't cope with version < 16 */
 542         if (be32_to_cpu(bph->version) < 16)
 543                 return -1;
 544
 545         /* clear the cxt */
 546         memset(cxt, 0, sizeof(*cxt));
 547
 548         /* alloc node_tbl to track node ptrs returned by ft_find_device */
 549         ++max_find_device;
 550         cxt->node_tbl = realloc_fn(NULL, max_find_device * sizeof(char *));
 551         if (!cxt->node_tbl)
 552                 return -1;
 553         memset(cxt->node_tbl, 0, max_find_device * sizeof(char *));
 554         cxt->node_max = max_find_device;
 555         cxt->nodes_used = 1;    /* don't use idx 0 b/c looks like NULL */
 556
 557         cxt->bph = bph;
 558         cxt->max_size = max_size;
 559         cxt->realloc = realloc_fn;
 560
 561         cxt->rgn[FT_RSVMAP].start = blob + be32_to_cpu(bph->off_mem_rsvmap);
 562         cxt->rgn[FT_RSVMAP].size = rsvmap_size(cxt);
 563         cxt->rgn[FT_STRUCT].start = blob + be32_to_cpu(bph->off_dt_struct);
 564         cxt->rgn[FT_STRUCT].size = struct_size(cxt);
 565         cxt->rgn[FT_STRINGS].start = blob + be32_to_cpu(bph->off_dt_strings);
 566         cxt->rgn[FT_STRINGS].size = be32_to_cpu(bph->dt_strings_size);
 567
 568         cxt->p = cxt->rgn[FT_STRUCT].start;
 569         cxt->str_anchor = cxt->rgn[FT_STRINGS].start;
 570
 571         return 0;
 572 }
 573
 574 /* add a reserver physical area to the rsvmap */
 575 int ft_add_rsvmap(struct ft_cxt *cxt, u64 physaddr, u64 size)
 576 {
 577         char *p;
 578         struct ft_reserve *pres;
 579
 580         p = cxt->rgn[FT_RSVMAP].start + cxt->rgn[FT_RSVMAP].size
 581                 - sizeof(struct ft_reserve);
 582         if (!ft_make_space(cxt, &p, FT_RSVMAP, sizeof(struct ft_reserve)))
 583                 return -1;
 584
 585         pres = (struct ft_reserve *)p;
 586         pres->start = cpu_to_be64(physaddr);
 587         pres->len = cpu_to_be64(size);
 588
 589         return 0;
 590 }
 591
 592 void ft_begin_tree(struct ft_cxt *cxt)
 593 {
 594         cxt->p = ft_root_node(cxt);
 595 }
 596
 597 void ft_end_tree(struct ft_cxt *cxt)
 598 {
 599         struct boot_param_header *bph = cxt->bph;
 600         char *p, *oldstr, *str, *endp;
 601         unsigned long ssize;
 602         int adj;
 603
 604         if (!cxt->isordered)
 605                 return;         /* we haven't touched anything */
 606
 607         /* adjust string offsets */
 608         oldstr = cxt->rgn[FT_STRINGS].start;
 609         adj = cxt->str_anchor - oldstr;
 610         if (adj)
 611                 adjust_string_offsets(cxt, adj);
 612
 613         /* make strings end on 8-byte boundary */
 614         ssize = cxt->rgn[FT_STRINGS].size;
 615         endp = (char *)_ALIGN((unsigned long)cxt->rgn[FT_STRUCT].start
 616                         + cxt->rgn[FT_STRUCT].size + ssize, 8);
 617         str = endp - ssize;
 618
 619         /* move strings down to end of structs */
 620         memmove(str, oldstr, ssize);
 621         cxt->str_anchor = str;
 622         cxt->rgn[FT_STRINGS].start = str;
 623
 624         /* fill in header fields */
 625         p = (char *)bph;
 626         bph->totalsize = cpu_to_be32(endp - p);
 627         bph->off_mem_rsvmap = cpu_to_be32(cxt->rgn[FT_RSVMAP].start - p);
 628         bph->off_dt_struct = cpu_to_be32(cxt->rgn[FT_STRUCT].start - p);
 629         bph->off_dt_strings = cpu_to_be32(cxt->rgn[FT_STRINGS].start - p);
 630         bph->dt_strings_size = cpu_to_be32(ssize);
 631 }
 632
 633 void *ft_find_device(struct ft_cxt *cxt, const void *top, const char *srch_path)
 634 {
 635         char *node;
 636
 637         if (top) {
 638                 node = ft_node_ph2node(cxt, top);
 639                 if (node == NULL)
 640                         return NULL;
 641         } else {
 642                 node = ft_root_node(cxt);
 643         }
 644
 645         node = ft_find_descendent(cxt, node, srch_path);
 646         return ft_get_phandle(cxt, node);
 647 }
 648
 649 void *ft_find_descendent(struct ft_cxt *cxt, void *top, const char *srch_path)
 650 {
 651         struct ft_atom atom;
 652         char *p;
 653         const char *cp, *q;
 654         int cl;
 655         int depth = -1;
 656         int dmatch = 0;
 657         const char *path_comp[FT_MAX_DEPTH];
 658
 659         cp = srch_path;
 660         cl = 0;
 661         p = top;
 662
 663         while ((p = ft_next(cxt, p, &atom)) != NULL) {
 664                 switch (atom.tag) {
 665                 case OF_DT_BEGIN_NODE:
 666                         ++depth;
 667                         if (depth != dmatch)
 668                                 break;
 669                         cxt->genealogy[depth] = atom.data;
 670                         cxt->genealogy[depth + 1] = NULL;
 671                         if (depth && !(strncmp(atom.name, cp, cl) == 0
 672                                         && (atom.name[cl] == '/'
 673                                                 || atom.name[cl] == '\0'
 674                                                 || atom.name[cl] == '@')))
 675                                 break;
 676                         path_comp[dmatch] = cp;
 677                         /* it matches so far, advance to next path component */
 678                         cp += cl;
 679                         /* skip slashes */
 680                         while (*cp == '/')
 681                                 ++cp;
 682                         /* we're done if this is the end of the string */
 683                         if (*cp == 0)
 684                                 return atom.data;
 685                         /* look for end of this component */
 686                         q = strchr(cp, '/');
 687                         if (q)
 688                                 cl = q - cp;
 689                         else
 690                                 cl = strlen(cp);
 691                         ++dmatch;
 692                         break;
 693                 case OF_DT_END_NODE:
 694                         if (depth == 0)
 695                                 return NULL;
 696                         if (dmatch > depth) {
 697                                 --dmatch;
 698                                 cl = cp - path_comp[dmatch] - 1;
 699                                 cp = path_comp[dmatch];
 700                                 while (cl > 0 && cp[cl - 1] == '/')
 701                                         --cl;
 702                         }
 703                         --depth;
 704                         break;
 705                 }
 706         }
 707         return NULL;
 708 }
 709
 710 void *__ft_get_parent(struct ft_cxt *cxt, void *node)
 711 {
 712         int d;
 713         struct ft_atom atom;
 714         char *p;
 715
 716         for (d = 0; cxt->genealogy[d] != NULL; ++d)
 717                 if (cxt->genealogy[d] == node)
 718                         return d > 0 ? cxt->genealogy[d - 1] : NULL;
 719
 720         /* have to do it the hard way... */
 721         p = ft_root_node(cxt);
 722         d = 0;
 723         while ((p = ft_next(cxt, p, &atom)) != NULL) {
 724                 switch (atom.tag) {
 725                 case OF_DT_BEGIN_NODE:
 726                         cxt->genealogy[d] = atom.data;
 727                         if (node == atom.data) {
 728                                 /* found it */
 729                                 cxt->genealogy[d + 1] = NULL;
 730                                 return d > 0 ? cxt->genealogy[d - 1] : NULL;
 731                         }
 732                         ++d;
 733                         break;
 734                 case OF_DT_END_NODE:
 735                         --d;
 736                         break;
 737                 }
 738         }
 739         return NULL;
 740 }
 741
 742 void *ft_get_parent(struct ft_cxt *cxt, const void *phandle)
 743 {
 744         void *node = ft_node_ph2node(cxt, phandle);
 745         if (node == NULL)
 746                 return NULL;
 747
 748         node = __ft_get_parent(cxt, node);
 749         return ft_get_phandle(cxt, node);
 750 }
 751
 752 static const void *__ft_get_prop(struct ft_cxt *cxt, void *node,
 753                                  const char *propname, unsigned int *len)
 754 {
 755         struct ft_atom atom;
 756         int depth = 0;
 757
 758         while ((node = ft_next(cxt, node, &atom)) != NULL) {
 759                 switch (atom.tag) {
 760                 case OF_DT_BEGIN_NODE:
 761                         ++depth;
 762                         break;
 763
 764                 case OF_DT_PROP:
 765                         if (depth != 1 || strcmp(atom.name, propname))
 766                                 break;
 767
 768                         if (len)
 769                                 *len = atom.size;
 770
 771                         return atom.data;
 772
 773                 case OF_DT_END_NODE:
 774                         if (--depth <= 0)
 775                                 return NULL;
 776                 }
 777         }
 778
 779         return NULL;
 780 }
 781
 782 int ft_get_prop(struct ft_cxt *cxt, const void *phandle, const char *propname,
 783                 void *buf, const unsigned int buflen)
 784 {
 785         const void *data;
 786         unsigned int size;
 787
 788         void *node = ft_node_ph2node(cxt, phandle);
 789         if (!node)
 790                 return -1;
 791
 792         data = __ft_get_prop(cxt, node, propname, &size);
 793         if (data) {
 794                 unsigned int clipped_size = min(size, buflen);
 795                 memcpy(buf, data, clipped_size);
 796                 return size;
 797         }
 798
 799         return -1;
 800 }
 801
 802 void *__ft_find_node_by_prop_value(struct ft_cxt *cxt, void *prev,
 803                                    const char *propname, const char *propval,
 804                                    unsigned int proplen)
 805 {
 806         struct ft_atom atom;
 807         char *p = ft_root_node(cxt);
 808         char *next;
 809         int past_prev = prev ? 0 : 1;
 810         int depth = -1;
 811
 812         while ((next = ft_next(cxt, p, &atom)) != NULL) {
 813                 const void *data;
 814                 unsigned int size;
 815
 816                 switch (atom.tag) {
 817                 case OF_DT_BEGIN_NODE:
 818                         depth++;
 819
 820                         if (prev == p) {
 821                                 past_prev = 1;
 822                                 break;
 823                         }
 824
 825                         if (!past_prev || depth < 1)
 826                                 break;
 827
 828                         data = __ft_get_prop(cxt, p, propname, &size);
 829                         if (!data || size != proplen)
 830                                 break;
 831                         if (memcmp(data, propval, size))
 832                                 break;
 833
 834                         return p;
 835
 836                 case OF_DT_END_NODE:
 837                         if (depth-- == 0)
 838                                 return NULL;
 839
 840                         break;
 841                 }
 842
 843                 p = next;
 844         }
 845
 846         return NULL;
 847 }
 848
 849 void *ft_find_node_by_prop_value(struct ft_cxt *cxt, const void *prev,
 850                                  const char *propname, const char *propval,
 851                                  int proplen)
 852 {
 853         void *node = NULL;
 854
 855         if (prev) {
 856                 node = ft_node_ph2node(cxt, prev);
 857
 858                 if (!node)
 859                         return NULL;
 860         }
 861
 862         node = __ft_find_node_by_prop_value(cxt, node, propname,
 863                                             propval, proplen);
 864         return ft_get_phandle(cxt, node);
 865 }
 866
 867 int ft_set_prop(struct ft_cxt *cxt, const void *phandle, const char *propname,
 868                 const void *buf, const unsigned int buflen)
 869 {
 870         struct ft_atom atom;
 871         void *node;
 872         char *p, *next;
 873         int nextra;
 874
 875         node = ft_node_ph2node(cxt, phandle);
 876         if (node == NULL)
 877                 return -1;
 878
 879         next = ft_next(cxt, node, &atom);
 880         if (atom.tag != OF_DT_BEGIN_NODE)
 881                 /* phandle didn't point to a node */
 882                 return -1;
 883         p = next;
 884
 885         while ((next = ft_next(cxt, p, &atom)) != NULL) {
 886                 switch (atom.tag) {
 887                 case OF_DT_BEGIN_NODE: /* properties must go before subnodes */
 888                 case OF_DT_END_NODE:
 889                         /* haven't found the property, insert here */
 890                         cxt->p = p;
 891                         return ft_prop(cxt, propname, buf, buflen);
 892                 case OF_DT_PROP:
 893                         if (strcmp(atom.name, propname))
 894                                 break;
 895                         /* found an existing property, overwrite it */
 896                         nextra = _ALIGN(buflen, 4) - _ALIGN(atom.size, 4);
 897                         cxt->p = atom.data;
 898                         if (nextra && !ft_make_space(cxt, &cxt->p, FT_STRUCT,
 899                                                 nextra))
 900                                 return -1;
 901                         *(u32 *) (cxt->p - 8) = cpu_to_be32(buflen);
 902                         ft_put_bin(cxt, buf, buflen);
 903                         return 0;
 904                 }
 905                 p = next;
 906         }
 907         return -1;
 908 }
 909
 910 int ft_del_prop(struct ft_cxt *cxt, const void *phandle, const char *propname)
 911 {
 912         struct ft_atom atom;
 913         void *node;
 914         char *p, *next;
 915         int size;
 916
 917         node = ft_node_ph2node(cxt, phandle);
 918         if (node == NULL)
 919                 return -1;
 920
 921         p = node;
 922         while ((next = ft_next(cxt, p, &atom)) != NULL) {
 923                 switch (atom.tag) {
 924                 case OF_DT_BEGIN_NODE:
 925                 case OF_DT_END_NODE:
 926                         return -1;
 927                 case OF_DT_PROP:
 928                         if (strcmp(atom.name, propname))
 929                                 break;
 930                         /* found the property, remove it */
 931                         size = 12 + -_ALIGN(atom.size, 4);
 932                         cxt->p = p;
 933                         if (!ft_make_space(cxt, &cxt->p, FT_STRUCT, -size))
 934                                 return -1;
 935                         return 0;
 936                 }
 937                 p = next;
 938         }
 939         return -1;
 940 }
 941
 942 void *ft_create_node(struct ft_cxt *cxt, const void *parent, const char *name)
 943 {
 944         struct ft_atom atom;
 945         char *p, *next, *ret;
 946         int depth = 0;
 947
 948         if (parent) {
 949                 p = ft_node_ph2node(cxt, parent);
 950                 if (!p)
 951                         return NULL;
 952         } else {
 953                 p = ft_root_node(cxt);
 954         }
 955
 956         while ((next = ft_next(cxt, p, &atom)) != NULL) {
 957                 switch (atom.tag) {
 958                 case OF_DT_BEGIN_NODE:
 959                         ++depth;
 960                         if (depth == 1 && strcmp(atom.name, name) == 0)
 961                                 /* duplicate node name, return error */
 962                                 return NULL;
 963                         break;
 964                 case OF_DT_END_NODE:
 965                         --depth;
 966                         if (depth > 0)
 967                                 break;
 968                         /* end of node, insert here */
 969                         cxt->p = p;
 970                         ret = ft_begin_node(cxt, name);
 971                         ft_end_node(cxt);
 972                         return ft_get_phandle(cxt, ret);
 973                 }
 974                 p = next;
 975         }
 976         return NULL;
 977 }
 978
 979 /* Returns the start of the path within the provided buffer, or NULL on
 980  * error.
 981  */
 982 char *ft_get_path(struct ft_cxt *cxt, const void *phandle,
 983                   char *buf, int len)
 984 {
 985         const char *path_comp[FT_MAX_DEPTH];
 986         struct ft_atom atom;
 987         char *p, *next, *pos;
 988         int depth = 0, i;
 989         void *node;
 990
 991         node = ft_node_ph2node(cxt, phandle);
 992         if (node == NULL)
 993                 return NULL;
 994
 995         p = ft_root_node(cxt);
 996
 997         while ((next = ft_next(cxt, p, &atom)) != NULL) {
 998                 switch (atom.tag) {
 999                 case OF_DT_BEGIN_NODE:
1000                         path_comp[depth++] = atom.name;
1001                         if (p == node)
1002                                 goto found;
1003
1004                         break;
1005
1006                 case OF_DT_END_NODE:
1007                         if (--depth == 0)
1008                                 return NULL;
1009                 }
1010
1011                 p = next;
1012         }
1013
1014 found:
1015         pos = buf;
1016         for (i = 1; i < depth; i++) {
1017                 int this_len;
1018
1019                 if (len <= 1)
1020                         return NULL;
1021
1022                 *pos++ = '/';
1023                 len--;
1024
1025                 strncpy(pos, path_comp[i], len);
1026
1027                 if (pos[len - 1] != 0)
1028                         return NULL;
1029
1030                 this_len = strlen(pos);
1031                 len -= this_len;
1032                 pos += this_len;
1033         }
1034
1035         return buf;
1036 }