drivers/of/fdt.c

   1 /*
   2  * Functions for working with the Flattened Device Tree data format
   3  *
   4  * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
   5  * benh@kernel.crashing.org
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/initrd.h>
  14 #include <linux/memblock.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_fdt.h>
  18 #include <linux/string.h>
  19 #include <linux/errno.h>
  20 #include <linux/slab.h>
  21 #include <linux/random.h>
  22
  23 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  24 #ifdef CONFIG_PPC
  25 #include <asm/machdep.h>
  26 #endif /* CONFIG_PPC */
  27
  28 #include <asm/page.h>
  29
  30 char *of_fdt_get_string(struct boot_param_header *blob, u32 offset)
  31 {
  32         return ((char *)blob) +
  33                 be32_to_cpu(blob->off_dt_strings) + offset;
  34 }
  35
  36 /**
  37  * of_fdt_get_property - Given a node in the given flat blob, return
  38  * the property ptr
  39  */
  40 void *of_fdt_get_property(struct boot_param_header *blob,
  41                        unsigned long node, const char *name,
  42                        unsigned long *size)
  43 {
  44         unsigned long p = node;
  45
  46         do {
  47                 u32 tag = be32_to_cpup((__be32 *)p);
  48                 u32 sz, noff;
  49                 const char *nstr;
  50
  51                 p += 4;
  52                 if (tag == OF_DT_NOP)
  53                         continue;
  54                 if (tag != OF_DT_PROP)
  55                         return NULL;
  56
  57                 sz = be32_to_cpup((__be32 *)p);
  58                 noff = be32_to_cpup((__be32 *)(p + 4));
  59                 p += 8;
  60                 if (be32_to_cpu(blob->version) < 0x10)
  61                         p = ALIGN(p, sz >= 8 ? 8 : 4);
  62
  63                 nstr = of_fdt_get_string(blob, noff);
  64                 if (nstr == NULL) {
  65                         pr_warning("Can't find property index name !\n");
  66                         return NULL;
  67                 }
  68                 if (strcmp(name, nstr) == 0) {
  69                         if (size)
  70                                 *size = sz;
  71                         return (void *)p;
  72                 }
  73                 p += sz;
  74                 p = ALIGN(p, 4);
  75         } while (1);
  76 }
  77
  78 /**
  79  * of_fdt_is_compatible - Return true if given node from the given blob has
  80  * compat in its compatible list
  81  * @blob: A device tree blob
  82  * @node: node to test
  83  * @compat: compatible string to compare with compatible list.
  84  *
  85  * On match, returns a non-zero value with smaller values returned for more
  86  * specific compatible values.
  87  */
  88 int of_fdt_is_compatible(struct boot_param_header *blob,
  89                       unsigned long node, const char *compat)
  90 {
  91         const char *cp;
  92         unsigned long cplen, l, score = 0;
  93
  94         cp = of_fdt_get_property(blob, node, "compatible", &cplen);
  95         if (cp == NULL)
  96                 return 0;
  97         while (cplen > 0) {
  98                 score++;
  99                 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 100                         return score;
 101                 l = strlen(cp) + 1;
 102                 cp += l;
 103                 cplen -= l;
 104         }
 105
 106         return 0;
 107 }
 108
 109 /**
 110  * of_fdt_match - Return true if node matches a list of compatible values
 111  */
 112 int of_fdt_match(struct boot_param_header *blob, unsigned long node,
 113                  const char *const *compat)
 114 {
 115         unsigned int tmp, score = 0;
 116
 117         if (!compat)
 118                 return 0;
 119
 120         while (*compat) {
 121                 tmp = of_fdt_is_compatible(blob, node, *compat);
 122                 if (tmp && (score == 0 || (tmp < score)))
 123                         score = tmp;
 124                 compat++;
 125         }
 126
 127         return score;
 128 }
 129
 130 static void *unflatten_dt_alloc(void **mem, unsigned long size,
 131                                        unsigned long align)
 132 {
 133         void *res;
 134
 135         *mem = PTR_ALIGN(*mem, align);
 136         res = *mem;
 137         *mem += size;
 138
 139         return res;
 140 }
 141
 142 /**
 143  * unflatten_dt_node - Alloc and populate a device_node from the flat tree
 144  * @blob: The parent device tree blob
 145  * @mem: Memory chunk to use for allocating device nodes and properties
 146  * @p: pointer to node in flat tree
 147  * @dad: Parent struct device_node
 148  * @allnextpp: pointer to ->allnext from last allocated device_node
 149  * @fpsize: Size of the node path up at the current depth.
 150  */
 151 static void * unflatten_dt_node(struct boot_param_header *blob,
 152                                 void *mem,
 153                                 void **p,
 154                                 struct device_node *dad,
 155                                 struct device_node ***allnextpp,
 156                                 unsigned long fpsize)
 157 {
 158         struct device_node *np;
 159         struct property *pp, **prev_pp = NULL;
 160         char *pathp;
 161         u32 tag;
 162         unsigned int l, allocl;
 163         int has_name = 0;
 164         int new_format = 0;
 165
 166         tag = be32_to_cpup(*p);
 167         if (tag != OF_DT_BEGIN_NODE) {
 168                 pr_err("Weird tag at start of node: %x\n", tag);
 169                 return mem;
 170         }
 171         *p += 4;
 172         pathp = *p;
 173         l = allocl = strlen(pathp) + 1;
 174         *p = PTR_ALIGN(*p + l, 4);
 175
 176         /* version 0x10 has a more compact unit name here instead of the full
 177          * path. we accumulate the full path size using "fpsize", we'll rebuild
 178          * it later. We detect this because the first character of the name is
 179          * not '/'.
 180          */
 181         if ((*pathp) != '/') {
 182                 new_format = 1;
 183                 if (fpsize == 0) {
 184                         /* root node: special case. fpsize accounts for path
 185                          * plus terminating zero. root node only has '/', so
 186                          * fpsize should be 2, but we want to avoid the first
 187                          * level nodes to have two '/' so we use fpsize 1 here
 188                          */
 189                         fpsize = 1;
 190                         allocl = 2;
 191                         l = 1;
 192                         *pathp = '\0';
 193                 } else {
 194                         /* account for '/' and path size minus terminal 0
 195                          * already in 'l'
 196                          */
 197                         fpsize += l;
 198                         allocl = fpsize;
 199                 }
 200         }
 201
 202         np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
 203                                 __alignof__(struct device_node));
 204         if (allnextpp) {
 205                 char *fn;
 206                 np->full_name = fn = ((char *)np) + sizeof(*np);
 207                 if (new_format) {
 208                         /* rebuild full path for new format */
 209                         if (dad && dad->parent) {
 210                                 strcpy(fn, dad->full_name);
 211 #ifdef DEBUG
 212                                 if ((strlen(fn) + l + 1) != allocl) {
 213                                         pr_debug("%s: p: %d, l: %d, a: %d\n",
 214                                                 pathp, (int)strlen(fn),
 215                                                 l, allocl);
 216                                 }
 217 #endif
 218                                 fn += strlen(fn);
 219                         }
 220                         *(fn++) = '/';
 221                 }
 222                 memcpy(fn, pathp, l);
 223
 224                 prev_pp = &np->properties;
 225                 **allnextpp = np;
 226                 *allnextpp = &np->allnext;
 227                 if (dad != NULL) {
 228                         np->parent = dad;
 229                         /* we temporarily use the next field as `last_child'*/
 230                         if (dad->next == NULL)
 231                                 dad->child = np;
 232                         else
 233                                 dad->next->sibling = np;
 234                         dad->next = np;
 235                 }
 236                 kref_init(&np->kref);
 237         }
 238         /* process properties */
 239         while (1) {
 240                 u32 sz, noff;
 241                 char *pname;
 242
 243                 tag = be32_to_cpup(*p);
 244                 if (tag == OF_DT_NOP) {
 245                         *p += 4;
 246                         continue;
 247                 }
 248                 if (tag != OF_DT_PROP)
 249                         break;
 250                 *p += 4;
 251                 sz = be32_to_cpup(*p);
 252                 noff = be32_to_cpup(*p + 4);
 253                 *p += 8;
 254                 if (be32_to_cpu(blob->version) < 0x10)
 255                         *p = PTR_ALIGN(*p, sz >= 8 ? 8 : 4);
 256
 257                 pname = of_fdt_get_string(blob, noff);
 258                 if (pname == NULL) {
 259                         pr_info("Can't find property name in list !\n");
 260                         break;
 261                 }
 262                 if (strcmp(pname, "name") == 0)
 263                         has_name = 1;
 264                 l = strlen(pname) + 1;
 265                 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
 266                                         __alignof__(struct property));
 267                 if (allnextpp) {
 268                         /* We accept flattened tree phandles either in
 269                          * ePAPR-style "phandle" properties, or the
 270                          * legacy "linux,phandle" properties.  If both
 271                          * appear and have different values, things
 272                          * will get weird.  Don't do that. */
 273                         if ((strcmp(pname, "phandle") == 0) ||
 274                             (strcmp(pname, "linux,phandle") == 0)) {
 275                                 if (np->phandle == 0)
 276                                         np->phandle = be32_to_cpup((__be32*)*p);
 277                         }
 278                         /* And we process the "ibm,phandle" property
 279                          * used in pSeries dynamic device tree
 280                          * stuff */
 281                         if (strcmp(pname, "ibm,phandle") == 0)
 282                                 np->phandle = be32_to_cpup((__be32 *)*p);
 283                         pp->name = pname;
 284                         pp->length = sz;
 285                         pp->value = *p;
 286                         *prev_pp = pp;
 287                         prev_pp = &pp->next;
 288                 }
 289                 *p = PTR_ALIGN((*p) + sz, 4);
 290         }
 291         /* with version 0x10 we may not have the name property, recreate
 292          * it here from the unit name if absent
 293          */
 294         if (!has_name) {
 295                 char *p1 = pathp, *ps = pathp, *pa = NULL;
 296                 int sz;
 297
 298                 while (*p1) {
 299                         if ((*p1) == '@')
 300                                 pa = p1;
 301                         if ((*p1) == '/')
 302                                 ps = p1 + 1;
 303                         p1++;
 304                 }
 305                 if (pa < ps)
 306                         pa = p1;
 307                 sz = (pa - ps) + 1;
 308                 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
 309                                         __alignof__(struct property));
 310                 if (allnextpp) {
 311                         pp->name = "name";
 312                         pp->length = sz;
 313                         pp->value = pp + 1;
 314                         *prev_pp = pp;
 315                         prev_pp = &pp->next;
 316                         memcpy(pp->value, ps, sz - 1);
 317                         ((char *)pp->value)[sz - 1] = 0;
 318                         pr_debug("fixed up name for %s -> %s\n", pathp,
 319                                 (char *)pp->value);
 320                 }
 321         }
 322         if (allnextpp) {
 323                 *prev_pp = NULL;
 324                 np->name = of_get_property(np, "name", NULL);
 325                 np->type = of_get_property(np, "device_type", NULL);
 326
 327                 if (!np->name)
 328                         np->name = "<NULL>";
 329                 if (!np->type)
 330                         np->type = "<NULL>";
 331         }
 332         while (tag == OF_DT_BEGIN_NODE || tag == OF_DT_NOP) {
 333                 if (tag == OF_DT_NOP)
 334                         *p += 4;
 335                 else
 336                         mem = unflatten_dt_node(blob, mem, p, np, allnextpp,
 337                                                 fpsize);
 338                 tag = be32_to_cpup(*p);
 339         }
 340         if (tag != OF_DT_END_NODE) {
 341                 pr_err("Weird tag at end of node: %x\n", tag);
 342                 return mem;
 343         }
 344         *p += 4;
 345         return mem;
 346 }
 347
 348 /**
 349  * __unflatten_device_tree - create tree of device_nodes from flat blob
 350  *
 351  * unflattens a device-tree, creating the
 352  * tree of struct device_node. It also fills the "name" and "type"
 353  * pointers of the nodes so the normal device-tree walking functions
 354  * can be used.
 355  * @blob: The blob to expand
 356  * @mynodes: The device_node tree created by the call
 357  * @dt_alloc: An allocator that provides a virtual address to memory
 358  * for the resulting tree
 359  */
 360 static void __unflatten_device_tree(struct boot_param_header *blob,
 361                              struct device_node **mynodes,
 362                              void * (*dt_alloc)(u64 size, u64 align))
 363 {
 364         unsigned long size;
 365         void *start, *mem;
 366         struct device_node **allnextp = mynodes;
 367
 368         pr_debug(" -> unflatten_device_tree()\n");
 369
 370         if (!blob) {
 371                 pr_debug("No device tree pointer\n");
 372                 return;
 373         }
 374
 375         pr_debug("Unflattening device tree:\n");
 376         pr_debug("magic: %08x\n", be32_to_cpu(blob->magic));
 377         pr_debug("size: %08x\n", be32_to_cpu(blob->totalsize));
 378         pr_debug("version: %08x\n", be32_to_cpu(blob->version));
 379
 380         if (be32_to_cpu(blob->magic) != OF_DT_HEADER) {
 381                 pr_err("Invalid device tree blob header\n");
 382                 return;
 383         }
 384
 385         /* First pass, scan for size */
 386         start = ((void *)blob) + be32_to_cpu(blob->off_dt_struct);
 387         size = (unsigned long)unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
 388         size = ALIGN(size, 4);
 389
 390         pr_debug("  size is %lx, allocating...\n", size);
 391
 392         /* Allocate memory for the expanded device tree */
 393         mem = dt_alloc(size + 4, __alignof__(struct device_node));
 394         memset(mem, 0, size);
 395
 396         *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 397
 398         pr_debug("  unflattening %p...\n", mem);
 399
 400         /* Second pass, do actual unflattening */
 401         start = ((void *)blob) + be32_to_cpu(blob->off_dt_struct);
 402         unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
 403         if (be32_to_cpup(start) != OF_DT_END)
 404                 pr_warning("Weird tag at end of tree: %08x\n", be32_to_cpup(start));
 405         if (be32_to_cpup(mem + size) != 0xdeadbeef)
 406                 pr_warning("End of tree marker overwritten: %08x\n",
 407                            be32_to_cpup(mem + size));
 408         *allnextp = NULL;
 409
 410         pr_debug(" <- unflatten_device_tree()\n");
 411 }
 412
 413 static void *kernel_tree_alloc(u64 size, u64 align)
 414 {
 415         return kzalloc(size, GFP_KERNEL);
 416 }
 417
 418 /**
 419  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 420  *
 421  * unflattens the device-tree passed by the firmware, creating the
 422  * tree of struct device_node. It also fills the "name" and "type"
 423  * pointers of the nodes so the normal device-tree walking functions
 424  * can be used.
 425  */
 426 void of_fdt_unflatten_tree(unsigned long *blob,
 427                         struct device_node **mynodes)
 428 {
 429         struct boot_param_header *device_tree =
 430                 (struct boot_param_header *)blob;
 431         __unflatten_device_tree(device_tree, mynodes, &kernel_tree_alloc);
 432 }
 433 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 434
 435 /* Everything below here references initial_boot_params directly. */
 436 int __initdata dt_root_addr_cells;
 437 int __initdata dt_root_size_cells;
 438
 439 struct boot_param_header *initial_boot_params;
 440
 441 #ifdef CONFIG_OF_EARLY_FLATTREE
 442
 443 /**
 444  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 445  * @it: callback function
 446  * @data: context data pointer
 447  *
 448  * This function is used to scan the flattened device-tree, it is
 449  * used to extract the memory information at boot before we can
 450  * unflatten the tree
 451  */
 452 int __init of_scan_flat_dt(int (*it)(unsigned long node,
 453                                      const char *uname, int depth,
 454                                      void *data),
 455                            void *data)
 456 {
 457         unsigned long p = ((unsigned long)initial_boot_params) +
 458                 be32_to_cpu(initial_boot_params->off_dt_struct);
 459         int rc = 0;
 460         int depth = -1;
 461
 462         do {
 463                 u32 tag = be32_to_cpup((__be32 *)p);
 464                 const char *pathp;
 465
 466                 p += 4;
 467                 if (tag == OF_DT_END_NODE) {
 468                         depth--;
 469                         continue;
 470                 }
 471                 if (tag == OF_DT_NOP)
 472                         continue;
 473                 if (tag == OF_DT_END)
 474                         break;
 475                 if (tag == OF_DT_PROP) {
 476                         u32 sz = be32_to_cpup((__be32 *)p);
 477                         p += 8;
 478                         if (be32_to_cpu(initial_boot_params->version) < 0x10)
 479                                 p = ALIGN(p, sz >= 8 ? 8 : 4);
 480                         p += sz;
 481                         p = ALIGN(p, 4);
 482                         continue;
 483                 }
 484                 if (tag != OF_DT_BEGIN_NODE) {
 485                         pr_err("Invalid tag %x in flat device tree!\n", tag);
 486                         return -EINVAL;
 487                 }
 488                 depth++;
 489                 pathp = (char *)p;
 490                 p = ALIGN(p + strlen(pathp) + 1, 4);
 491                 if (*pathp == '/')
 492                         pathp = kbasename(pathp);
 493                 rc = it(p, pathp, depth, data);
 494                 if (rc != 0)
 495                         break;
 496         } while (1);
 497
 498         return rc;
 499 }
 500
 501 /**
 502  * of_get_flat_dt_root - find the root node in the flat blob
 503  */
 504 unsigned long __init of_get_flat_dt_root(void)
 505 {
 506         unsigned long p = ((unsigned long)initial_boot_params) +
 507                 be32_to_cpu(initial_boot_params->off_dt_struct);
 508
 509         while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
 510                 p += 4;
 511         BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
 512         p += 4;
 513         return ALIGN(p + strlen((char *)p) + 1, 4);
 514 }
 515
 516 /**
 517  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 518  *
 519  * This function can be used within scan_flattened_dt callback to get
 520  * access to properties
 521  */
 522 void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 523                                  unsigned long *size)
 524 {
 525         return of_fdt_get_property(initial_boot_params, node, name, size);
 526 }
 527
 528 /**
 529  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 530  * @node: node to test
 531  * @compat: compatible string to compare with compatible list.
 532  */
 533 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 534 {
 535         return of_fdt_is_compatible(initial_boot_params, node, compat);
 536 }
 537
 538 /**
 539  * of_flat_dt_match - Return true if node matches a list of compatible values
 540  */
 541 int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 542 {
 543         return of_fdt_match(initial_boot_params, node, compat);
 544 }
 545
 546 struct fdt_scan_status {
 547         const char *name;
 548         int namelen;
 549         int depth;
 550         int found;
 551         int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 552         void *data;
 553 };
 554
 555 /**
 556  * fdt_scan_node_by_path - iterator for of_scan_flat_dt_by_path function
 557  */
 558 static int __init fdt_scan_node_by_path(unsigned long node, const char *uname,
 559                                         int depth, void *data)
 560 {
 561         struct fdt_scan_status *st = data;
 562
 563         /*
 564          * if scan at the requested fdt node has been completed,
 565          * return -ENXIO to abort further scanning
 566          */
 567         if (depth <= st->depth)
 568                 return -ENXIO;
 569
 570         /* requested fdt node has been found, so call iterator function */
 571         if (st->found)
 572                 return st->iterator(node, uname, depth, st->data);
 573
 574         /* check if scanning automata is entering next level of fdt nodes */
 575         if (depth == st->depth + 1 &&
 576             strncmp(st->name, uname, st->namelen) == 0 &&
 577             uname[st->namelen] == 0) {
 578                 st->depth += 1;
 579                 if (st->name[st->namelen] == 0) {
 580                         st->found = 1;
 581                 } else {
 582                         const char *next = st->name + st->namelen + 1;
 583                         st->name = next;
 584                         st->namelen = strcspn(next, "/");
 585                 }
 586                 return 0;
 587         }
 588
 589         /* scan next fdt node */
 590         return 0;
 591 }
 592
 593 /**
 594  * of_scan_flat_dt_by_path - scan flattened tree blob and call callback on each
 595  *                           child of the given path.
 596  * @path: path to start searching for children
 597  * @it: callback function
 598  * @data: context data pointer
 599  *
 600  * This function is used to scan the flattened device-tree starting from the
 601  * node given by path. It is used to extract information (like reserved
 602  * memory), which is required on ealy boot before we can unflatten the tree.
 603  */
 604 int __init of_scan_flat_dt_by_path(const char *path,
 605         int (*it)(unsigned long node, const char *name, int depth, void *data),
 606         void *data)
 607 {
 608         struct fdt_scan_status st = {path, 0, -1, 0, it, data};
 609         int ret = 0;
 610
 611         if (initial_boot_params)
 612                 ret = of_scan_flat_dt(fdt_scan_node_by_path, &st);
 613
 614         if (!st.found)
 615                 return -ENOENT;
 616         else if (ret == -ENXIO) /* scan has been completed */
 617                 return 0;
 618         else
 619                 return ret;
 620 }
 621
 622 #ifdef CONFIG_BLK_DEV_INITRD
 623 /**
 624  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 625  * @node: reference to node containing initrd location ('chosen')
 626  */
 627 void __init early_init_dt_check_for_initrd(unsigned long node)
 628 {
 629         u64 start, end;
 630         unsigned long len;
 631         __be32 *prop;
 632
 633         pr_debug("Looking for initrd properties... ");
 634
 635         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 636         if (!prop)
 637                 return;
 638         start = of_read_number(prop, len/4);
 639
 640         prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 641         if (!prop)
 642                 return;
 643         end = of_read_number(prop, len/4);
 644
 645         early_init_dt_setup_initrd_arch(start, end);
 646         pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 647                  (unsigned long long)start, (unsigned long long)end);
 648 }
 649 #else
 650 inline void early_init_dt_check_for_initrd(unsigned long node)
 651 {
 652 }
 653 #endif /* CONFIG_BLK_DEV_INITRD */
 654
 655 /**
 656  * early_init_dt_scan_root - fetch the top level address and size cells
 657  */
 658 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 659                                    int depth, void *data)
 660 {
 661         __be32 *prop;
 662
 663         if (depth != 0)
 664                 return 0;
 665
 666         dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 667         dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 668
 669         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 670         if (prop)
 671                 dt_root_size_cells = be32_to_cpup(prop);
 672         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 673
 674         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 675         if (prop)
 676                 dt_root_addr_cells = be32_to_cpup(prop);
 677         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 678
 679         /* break now */
 680         return 1;
 681 }
 682
 683 u64 __init dt_mem_next_cell(int s, __be32 **cellp)
 684 {
 685         __be32 *p = *cellp;
 686
 687         *cellp = p + s;
 688         return of_read_number(p, s);
 689 }
 690
 691 /**
 692  * early_init_dt_scan_memory - Look for an parse memory nodes
 693  */
 694 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 695                                      int depth, void *data)
 696 {
 697         char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 698         __be32 *reg, *endp;
 699         unsigned long l;
 700
 701         /* We are scanning "memory" nodes only */
 702         if (type == NULL) {
 703                 /*
 704                  * The longtrail doesn't have a device_type on the
 705                  * /memory node, so look for the node called /memory@0.
 706                  */
 707                 if (depth != 1 || strcmp(uname, "memory@0") != 0)
 708                         return 0;
 709         } else if (strcmp(type, "memory") != 0)
 710                 return 0;
 711
 712         reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
 713         if (reg == NULL)
 714                 reg = of_get_flat_dt_prop(node, "reg", &l);
 715         if (reg == NULL)
 716                 return 0;
 717
 718         endp = reg + (l / sizeof(__be32));
 719
 720         pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
 721             uname, l, reg[0], reg[1], reg[2], reg[3]);
 722
 723         while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
 724                 u64 base, size;
 725
 726                 base = dt_mem_next_cell(dt_root_addr_cells, &reg);
 727                 size = dt_mem_next_cell(dt_root_size_cells, &reg);
 728
 729                 if (size == 0)
 730                         continue;
 731                 pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
 732                     (unsigned long long)size);
 733
 734                 early_init_dt_add_memory_arch(base, size);
 735         }
 736
 737         return 0;
 738 }
 739
 740 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
 741                                      int depth, void *data)
 742 {
 743         unsigned long l;
 744         char *p;
 745
 746         pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
 747
 748         if (depth != 1 || !data ||
 749             (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
 750                 return 0;
 751
 752         early_init_dt_check_for_initrd(node);
 753
 754         /* Retrieve command line */
 755         p = of_get_flat_dt_prop(node, "bootargs", &l);
 756         if (p != NULL && l > 0)
 757                 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
 758
 759         /*
 760          * CONFIG_CMDLINE is meant to be a default in case nothing else
 761          * managed to set the command line, unless CONFIG_CMDLINE_FORCE
 762          * is set in which case we override whatever was found earlier.
 763          */
 764 #ifdef CONFIG_CMDLINE
 765 #ifndef CONFIG_CMDLINE_FORCE
 766         if (!((char *)data)[0])
 767 #endif
 768                 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 769 #endif /* CONFIG_CMDLINE */
 770
 771         pr_debug("Command line is: %s\n", (char*)data);
 772
 773         /* break now */
 774         return 1;
 775 }
 776
 777 #ifdef CONFIG_HAVE_MEMBLOCK
 778 /*
 779  * called from unflatten_device_tree() to bootstrap devicetree itself
 780  * Architectures can override this definition if memblock isn't used
 781  */
 782 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
 783 {
 784         return __va(memblock_alloc(size, align));
 785 }
 786 #endif
 787
 788 bool __init early_init_dt_scan(void *params)
 789 {
 790         if (!params)
 791                 return false;
 792
 793         /* Setup flat device-tree pointer */
 794         initial_boot_params = params;
 795
 796         /* check device tree validity */
 797         if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) {
 798                 initial_boot_params = NULL;
 799                 return false;
 800         }
 801
 802         /* Retrieve various information from the /chosen node */
 803         of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
 804
 805         /* Initialize {size,address}-cells info */
 806         of_scan_flat_dt(early_init_dt_scan_root, NULL);
 807
 808         /* Setup memory, calling early_init_dt_add_memory_arch */
 809         of_scan_flat_dt(early_init_dt_scan_memory, NULL);
 810
 811         return true;
 812 }
 813
 814 /**
 815  * unflatten_device_tree - create tree of device_nodes from flat blob
 816  *
 817  * unflattens the device-tree passed by the firmware, creating the
 818  * tree of struct device_node. It also fills the "name" and "type"
 819  * pointers of the nodes so the normal device-tree walking functions
 820  * can be used.
 821  */
 822 void __init unflatten_device_tree(void)
 823 {
 824         __unflatten_device_tree(initial_boot_params, &of_allnodes,
 825                                 early_init_dt_alloc_memory_arch);
 826
 827         /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
 828         of_alias_scan(early_init_dt_alloc_memory_arch);
 829 }
 830
 831 /**
 832  * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
 833  *
 834  * Copies and unflattens the device-tree passed by the firmware, creating the
 835  * tree of struct device_node. It also fills the "name" and "type"
 836  * pointers of the nodes so the normal device-tree walking functions
 837  * can be used. This should only be used when the FDT memory has not been
 838  * reserved such is the case when the FDT is built-in to the kernel init
 839  * section. If the FDT memory is reserved already then unflatten_device_tree
 840  * should be used instead.
 841  */
 842 void __init unflatten_and_copy_device_tree(void)
 843 {
 844         int size = __be32_to_cpu(initial_boot_params->totalsize);
 845         void *dt = early_init_dt_alloc_memory_arch(size,
 846                 __alignof__(struct boot_param_header));
 847
 848         if (dt) {
 849                 memcpy(dt, initial_boot_params, size);
 850                 initial_boot_params = dt;
 851         }
 852         unflatten_device_tree();
 853 }
 854
 855 #endif /* CONFIG_OF_EARLY_FLATTREE */
 856
 857 /* Feed entire flattened device tree into the random pool */
 858 static int __init add_fdt_randomness(void)
 859 {
 860         if (initial_boot_params)
 861                 add_device_randomness(initial_boot_params,
 862                                 be32_to_cpu(initial_boot_params->totalsize));
 863
 864         return 0;
 865 }
 866 core_initcall(add_fdt_randomness);