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/of_reserved_mem.h>
  19 #include <linux/sizes.h>
  20 #include <linux/string.h>
  21 #include <linux/errno.h>
  22 #include <linux/slab.h>
  23
  24 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  25 #ifdef CONFIG_PPC
  26 #include <asm/machdep.h>
  27 #endif /* CONFIG_PPC */
  28
  29 #include <asm/page.h>
  30
  31 char *of_fdt_get_string(struct boot_param_header *blob, u32 offset)
  32 {
  33         return ((char *)blob) +
  34                 be32_to_cpu(blob->off_dt_strings) + offset;
  35 }
  36
  37 /**
  38  * of_fdt_get_property - Given a node in the given flat blob, return
  39  * the property ptr
  40  */
  41 void *of_fdt_get_property(struct boot_param_header *blob,
  42                        unsigned long node, const char *name,
  43                        unsigned long *size)
  44 {
  45         unsigned long p = node;
  46
  47         do {
  48                 u32 tag = be32_to_cpup((__be32 *)p);
  49                 u32 sz, noff;
  50                 const char *nstr;
  51
  52                 p += 4;
  53                 if (tag == OF_DT_NOP)
  54                         continue;
  55                 if (tag != OF_DT_PROP)
  56                         return NULL;
  57
  58                 sz = be32_to_cpup((__be32 *)p);
  59                 noff = be32_to_cpup((__be32 *)(p + 4));
  60                 p += 8;
  61                 if (be32_to_cpu(blob->version) < 0x10)
  62                         p = ALIGN(p, sz >= 8 ? 8 : 4);
  63
  64                 nstr = of_fdt_get_string(blob, noff);
  65                 if (nstr == NULL) {
  66                         pr_warning("Can't find property index name !\n");
  67                         return NULL;
  68                 }
  69                 if (strcmp(name, nstr) == 0) {
  70                         if (size)
  71                                 *size = sz;
  72                         return (void *)p;
  73                 }
  74                 p += sz;
  75                 p = ALIGN(p, 4);
  76         } while (1);
  77 }
  78
  79 /**
  80  * of_fdt_is_compatible - Return true if given node from the given blob has
  81  * compat in its compatible list
  82  * @blob: A device tree blob
  83  * @node: node to test
  84  * @compat: compatible string to compare with compatible list.
  85  *
  86  * On match, returns a non-zero value with smaller values returned for more
  87  * specific compatible values.
  88  */
  89 int of_fdt_is_compatible(struct boot_param_header *blob,
  90                       unsigned long node, const char *compat)
  91 {
  92         const char *cp;
  93         unsigned long cplen, l, score = 0;
  94
  95         cp = of_fdt_get_property(blob, node, "compatible", &cplen);
  96         if (cp == NULL)
  97                 return 0;
  98         while (cplen > 0) {
  99                 score++;
 100                 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 101                         return score;
 102                 l = strlen(cp) + 1;
 103                 cp += l;
 104                 cplen -= l;
 105         }
 106
 107         return 0;
 108 }
 109
 110 /**
 111  * of_fdt_match - Return true if node matches a list of compatible values
 112  */
 113 int of_fdt_match(struct boot_param_header *blob, unsigned long node,
 114                  const char *const *compat)
 115 {
 116         unsigned int tmp, score = 0;
 117
 118         if (!compat)
 119                 return 0;
 120
 121         while (*compat) {
 122                 tmp = of_fdt_is_compatible(blob, node, *compat);
 123                 if (tmp && (score == 0 || (tmp < score)))
 124                         score = tmp;
 125                 compat++;
 126         }
 127
 128         return score;
 129 }
 130
 131 static void *unflatten_dt_alloc(unsigned long *mem, unsigned long size,
 132                                        unsigned long align)
 133 {
 134         void *res;
 135
 136         *mem = ALIGN(*mem, align);
 137         res = (void *)*mem;
 138         *mem += size;
 139
 140         return res;
 141 }
 142
 143 /**
 144  * unflatten_dt_node - Alloc and populate a device_node from the flat tree
 145  * @blob: The parent device tree blob
 146  * @mem: Memory chunk to use for allocating device nodes and properties
 147  * @p: pointer to node in flat tree
 148  * @dad: Parent struct device_node
 149  * @allnextpp: pointer to ->allnext from last allocated device_node
 150  * @fpsize: Size of the node path up at the current depth.
 151  */
 152 static unsigned long unflatten_dt_node(struct boot_param_header *blob,
 153                                 unsigned long mem,
 154                                 unsigned long *p,
 155                                 struct device_node *dad,
 156                                 struct device_node ***allnextpp,
 157                                 unsigned long fpsize)
 158 {
 159         struct device_node *np;
 160         struct property *pp, **prev_pp = NULL;
 161         char *pathp;
 162         u32 tag;
 163         unsigned int l, allocl;
 164         int has_name = 0;
 165         int new_format = 0;
 166
 167         tag = be32_to_cpup((__be32 *)(*p));
 168         if (tag != OF_DT_BEGIN_NODE) {
 169                 pr_err("Weird tag at start of node: %x\n", tag);
 170                 return mem;
 171         }
 172         *p += 4;
 173         pathp = (char *)*p;
 174         l = allocl = strlen(pathp) + 1;
 175         *p = ALIGN(*p + l, 4);
 176
 177         /* version 0x10 has a more compact unit name here instead of the full
 178          * path. we accumulate the full path size using "fpsize", we'll rebuild
 179          * it later. We detect this because the first character of the name is
 180          * not '/'.
 181          */
 182         if ((*pathp) != '/') {
 183                 new_format = 1;
 184                 if (fpsize == 0) {
 185                         /* root node: special case. fpsize accounts for path
 186                          * plus terminating zero. root node only has '/', so
 187                          * fpsize should be 2, but we want to avoid the first
 188                          * level nodes to have two '/' so we use fpsize 1 here
 189                          */
 190                         fpsize = 1;
 191                         allocl = 2;
 192                         l = 1;
 193                         *pathp = '\0';
 194                 } else {
 195                         /* account for '/' and path size minus terminal 0
 196                          * already in 'l'
 197                          */
 198                         fpsize += l;
 199                         allocl = fpsize;
 200                 }
 201         }
 202
 203         np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
 204                                 __alignof__(struct device_node));
 205         if (allnextpp) {
 206                 char *fn;
 207                 memset(np, 0, sizeof(*np));
 208                 np->full_name = fn = ((char *)np) + sizeof(*np);
 209                 if (new_format) {
 210                         /* rebuild full path for new format */
 211                         if (dad && dad->parent) {
 212                                 strcpy(fn, dad->full_name);
 213 #ifdef DEBUG
 214                                 if ((strlen(fn) + l + 1) != allocl) {
 215                                         pr_debug("%s: p: %d, l: %d, a: %d\n",
 216                                                 pathp, (int)strlen(fn),
 217                                                 l, allocl);
 218                                 }
 219 #endif
 220                                 fn += strlen(fn);
 221                         }
 222                         *(fn++) = '/';
 223                 }
 224                 memcpy(fn, pathp, l);
 225
 226                 prev_pp = &np->properties;
 227                 **allnextpp = np;
 228                 *allnextpp = &np->allnext;
 229                 if (dad != NULL) {
 230                         np->parent = dad;
 231                         /* we temporarily use the next field as `last_child'*/
 232                         if (dad->next == NULL)
 233                                 dad->child = np;
 234                         else
 235                                 dad->next->sibling = np;
 236                         dad->next = np;
 237                 }
 238                 kref_init(&np->kref);
 239         }
 240         /* process properties */
 241         while (1) {
 242                 u32 sz, noff;
 243                 char *pname;
 244
 245                 tag = be32_to_cpup((__be32 *)(*p));
 246                 if (tag == OF_DT_NOP) {
 247                         *p += 4;
 248                         continue;
 249                 }
 250                 if (tag != OF_DT_PROP)
 251                         break;
 252                 *p += 4;
 253                 sz = be32_to_cpup((__be32 *)(*p));
 254                 noff = be32_to_cpup((__be32 *)((*p) + 4));
 255                 *p += 8;
 256                 if (be32_to_cpu(blob->version) < 0x10)
 257                         *p = ALIGN(*p, sz >= 8 ? 8 : 4);
 258
 259                 pname = of_fdt_get_string(blob, noff);
 260                 if (pname == NULL) {
 261                         pr_info("Can't find property name in list !\n");
 262                         break;
 263                 }
 264                 if (strcmp(pname, "name") == 0)
 265                         has_name = 1;
 266                 l = strlen(pname) + 1;
 267                 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
 268                                         __alignof__(struct property));
 269                 if (allnextpp) {
 270                         /* We accept flattened tree phandles either in
 271                          * ePAPR-style "phandle" properties, or the
 272                          * legacy "linux,phandle" properties.  If both
 273                          * appear and have different values, things
 274                          * will get weird.  Don't do that. */
 275                         if ((strcmp(pname, "phandle") == 0) ||
 276                             (strcmp(pname, "linux,phandle") == 0)) {
 277                                 if (np->phandle == 0)
 278                                         np->phandle = be32_to_cpup((__be32*)*p);
 279                         }
 280                         /* And we process the "ibm,phandle" property
 281                          * used in pSeries dynamic device tree
 282                          * stuff */
 283                         if (strcmp(pname, "ibm,phandle") == 0)
 284                                 np->phandle = be32_to_cpup((__be32 *)*p);
 285                         pp->name = pname;
 286                         pp->length = sz;
 287                         pp->value = (void *)*p;
 288                         *prev_pp = pp;
 289                         prev_pp = &pp->next;
 290                 }
 291                 *p = ALIGN((*p) + sz, 4);
 292         }
 293         /* with version 0x10 we may not have the name property, recreate
 294          * it here from the unit name if absent
 295          */
 296         if (!has_name) {
 297                 char *p1 = pathp, *ps = pathp, *pa = NULL;
 298                 int sz;
 299
 300                 while (*p1) {
 301                         if ((*p1) == '@')
 302                                 pa = p1;
 303                         if ((*p1) == '/')
 304                                 ps = p1 + 1;
 305                         p1++;
 306                 }
 307                 if (pa < ps)
 308                         pa = p1;
 309                 sz = (pa - ps) + 1;
 310                 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
 311                                         __alignof__(struct property));
 312                 if (allnextpp) {
 313                         pp->name = "name";
 314                         pp->length = sz;
 315                         pp->value = pp + 1;
 316                         *prev_pp = pp;
 317                         prev_pp = &pp->next;
 318                         memcpy(pp->value, ps, sz - 1);
 319                         ((char *)pp->value)[sz - 1] = 0;
 320                         pr_debug("fixed up name for %s -> %s\n", pathp,
 321                                 (char *)pp->value);
 322                 }
 323         }
 324         if (allnextpp) {
 325                 *prev_pp = NULL;
 326                 np->name = of_get_property(np, "name", NULL);
 327                 np->type = of_get_property(np, "device_type", NULL);
 328
 329                 if (!np->name)
 330                         np->name = "<NULL>";
 331                 if (!np->type)
 332                         np->type = "<NULL>";
 333         }
 334         while (tag == OF_DT_BEGIN_NODE || tag == OF_DT_NOP) {
 335                 if (tag == OF_DT_NOP)
 336                         *p += 4;
 337                 else
 338                         mem = unflatten_dt_node(blob, mem, p, np, allnextpp,
 339                                                 fpsize);
 340                 tag = be32_to_cpup((__be32 *)(*p));
 341         }
 342         if (tag != OF_DT_END_NODE) {
 343                 pr_err("Weird tag at end of node: %x\n", tag);
 344                 return mem;
 345         }
 346         *p += 4;
 347         return mem;
 348 }
 349
 350 /**
 351  * __unflatten_device_tree - create tree of device_nodes from flat blob
 352  *
 353  * unflattens a device-tree, creating the
 354  * tree of struct device_node. It also fills the "name" and "type"
 355  * pointers of the nodes so the normal device-tree walking functions
 356  * can be used.
 357  * @blob: The blob to expand
 358  * @mynodes: The device_node tree created by the call
 359  * @dt_alloc: An allocator that provides a virtual address to memory
 360  * for the resulting tree
 361  */
 362 static void __unflatten_device_tree(struct boot_param_header *blob,
 363                              struct device_node **mynodes,
 364                              void * (*dt_alloc)(u64 size, u64 align))
 365 {
 366         unsigned long start, mem, size;
 367         struct device_node **allnextp = mynodes;
 368
 369         pr_debug(" -> unflatten_device_tree()\n");
 370
 371         if (!blob) {
 372                 pr_debug("No device tree pointer\n");
 373                 return;
 374         }
 375
 376         pr_debug("Unflattening device tree:\n");
 377         pr_debug("magic: %08x\n", be32_to_cpu(blob->magic));
 378         pr_debug("size: %08x\n", be32_to_cpu(blob->totalsize));
 379         pr_debug("version: %08x\n", be32_to_cpu(blob->version));
 380
 381         if (be32_to_cpu(blob->magic) != OF_DT_HEADER) {
 382                 pr_err("Invalid device tree blob header\n");
 383                 return;
 384         }
 385
 386         /* First pass, scan for size */
 387         start = ((unsigned long)blob) +
 388                 be32_to_cpu(blob->off_dt_struct);
 389         size = unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
 390         size = (size | 3) + 1;
 391
 392         pr_debug("  size is %lx, allocating...\n", size);
 393
 394         /* Allocate memory for the expanded device tree */
 395         mem = (unsigned long)
 396                 dt_alloc(size + 4, __alignof__(struct device_node));
 397
 398         memset((void *)mem, 0, size);
 399
 400         ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
 401
 402         pr_debug("  unflattening %lx...\n", mem);
 403
 404         /* Second pass, do actual unflattening */
 405         start = ((unsigned long)blob) +
 406                 be32_to_cpu(blob->off_dt_struct);
 407         unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
 408         if (be32_to_cpup((__be32 *)start) != OF_DT_END)
 409                 pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
 410         if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
 411                 pr_warning("End of tree marker overwritten: %08x\n",
 412                            be32_to_cpu(((__be32 *)mem)[size / 4]));
 413         *allnextp = NULL;
 414
 415         pr_debug(" <- unflatten_device_tree()\n");
 416 }
 417
 418 static void *kernel_tree_alloc(u64 size, u64 align)
 419 {
 420         return kzalloc(size, GFP_KERNEL);
 421 }
 422
 423 /**
 424  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 425  *
 426  * unflattens the device-tree passed by the firmware, creating the
 427  * tree of struct device_node. It also fills the "name" and "type"
 428  * pointers of the nodes so the normal device-tree walking functions
 429  * can be used.
 430  */
 431 void of_fdt_unflatten_tree(unsigned long *blob,
 432                         struct device_node **mynodes)
 433 {
 434         struct boot_param_header *device_tree =
 435                 (struct boot_param_header *)blob;
 436         __unflatten_device_tree(device_tree, mynodes, &kernel_tree_alloc);
 437 }
 438 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 439
 440 /* Everything below here references initial_boot_params directly. */
 441 int __initdata dt_root_addr_cells;
 442 int __initdata dt_root_size_cells;
 443
 444 struct boot_param_header *initial_boot_params;
 445
 446 #ifdef CONFIG_OF_EARLY_FLATTREE
 447
 448 /**
 449  * res_mem_reserve_reg() - reserve all memory described in 'reg' property
 450  */
 451 static int __init __reserved_mem_reserve_reg(unsigned long node,
 452                                              const char *uname)
 453 {
 454         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 455         phys_addr_t base, size;
 456         unsigned long len;
 457         __be32 *prop;
 458         int nomap, first = 1;
 459
 460         prop = of_get_flat_dt_prop(node, "reg", &len);
 461         if (!prop)
 462                 return -ENOENT;
 463
 464         if (len && len % t_len != 0) {
 465                 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 466                        uname);
 467                 return -EINVAL;
 468         }
 469
 470         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 471
 472         while (len >= t_len) {
 473                 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 474                 size = dt_mem_next_cell(dt_root_size_cells, &prop);
 475
 476                 if (base && size &&
 477                     early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 478                         pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 479                                 uname, &base, (unsigned long)size / SZ_1M);
 480                 else
 481                         pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 482                                 uname, &base, (unsigned long)size / SZ_1M);
 483
 484                 len -= t_len;
 485                 if (first) {
 486                         fdt_reserved_mem_save_node(node, uname, base, size);
 487                         first = 0;
 488                 }
 489         }
 490         return 0;
 491 }
 492
 493 /**
 494  * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 495  * in /reserved-memory matches the values supported by the current implementation,
 496  * also check if ranges property has been provided
 497  */
 498 static int __reserved_mem_check_root(unsigned long node)
 499 {
 500         __be32 *prop;
 501
 502         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 503         if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 504                 return -EINVAL;
 505
 506         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 507         if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 508                 return -EINVAL;
 509
 510         prop = of_get_flat_dt_prop(node, "ranges", NULL);
 511         if (!prop)
 512                 return -EINVAL;
 513         return 0;
 514 }
 515
 516 /**
 517  * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 518  */
 519 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 520                                           int depth, void *data)
 521 {
 522         static int found;
 523         const char *status;
 524         int err;
 525
 526         if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 527                 if (__reserved_mem_check_root(node) != 0) {
 528                         pr_err("Reserved memory: unsupported node format, ignoring\n");
 529                         /* break scan */
 530                         return 1;
 531                 }
 532                 found = 1;
 533                 /* scan next node */
 534                 return 0;
 535         } else if (!found) {
 536                 /* scan next node */
 537                 return 0;
 538         } else if (found && depth < 2) {
 539                 /* scanning of /reserved-memory has been finished */
 540                 return 1;
 541         }
 542
 543         status = of_get_flat_dt_prop(node, "status", NULL);
 544         if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
 545                 return 0;
 546
 547         err = __reserved_mem_reserve_reg(node, uname);
 548         if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 549                 fdt_reserved_mem_save_node(node, uname, 0, 0);
 550
 551         /* scan next node */
 552         return 0;
 553 }
 554
 555 /**
 556  * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 557  *
 558  * This function grabs memory from early allocator for device exclusive use
 559  * defined in device tree structures. It should be called by arch specific code
 560  * once the early allocator (i.e. memblock) has been fully activated.
 561  */
 562 void __init early_init_fdt_scan_reserved_mem(void)
 563 {
 564         of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 565         fdt_init_reserved_mem();
 566 }
 567
 568 /**
 569  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 570  * @it: callback function
 571  * @data: context data pointer
 572  *
 573  * This function is used to scan the flattened device-tree, it is
 574  * used to extract the memory information at boot before we can
 575  * unflatten the tree
 576  */
 577 int __init of_scan_flat_dt(int (*it)(unsigned long node,
 578                                      const char *uname, int depth,
 579                                      void *data),
 580                            void *data)
 581 {
 582         unsigned long p = ((unsigned long)initial_boot_params) +
 583                 be32_to_cpu(initial_boot_params->off_dt_struct);
 584         int rc = 0;
 585         int depth = -1;
 586
 587         do {
 588                 u32 tag = be32_to_cpup((__be32 *)p);
 589                 const char *pathp;
 590
 591                 p += 4;
 592                 if (tag == OF_DT_END_NODE) {
 593                         depth--;
 594                         continue;
 595                 }
 596                 if (tag == OF_DT_NOP)
 597                         continue;
 598                 if (tag == OF_DT_END)
 599                         break;
 600                 if (tag == OF_DT_PROP) {
 601                         u32 sz = be32_to_cpup((__be32 *)p);
 602                         p += 8;
 603                         if (be32_to_cpu(initial_boot_params->version) < 0x10)
 604                                 p = ALIGN(p, sz >= 8 ? 8 : 4);
 605                         p += sz;
 606                         p = ALIGN(p, 4);
 607                         continue;
 608                 }
 609                 if (tag != OF_DT_BEGIN_NODE) {
 610                         pr_err("Invalid tag %x in flat device tree!\n", tag);
 611                         return -EINVAL;
 612                 }
 613                 depth++;
 614                 pathp = (char *)p;
 615                 p = ALIGN(p + strlen(pathp) + 1, 4);
 616                 if (*pathp == '/')
 617                         pathp = kbasename(pathp);
 618                 rc = it(p, pathp, depth, data);
 619                 if (rc != 0)
 620                         break;
 621         } while (1);
 622
 623         return rc;
 624 }
 625
 626 /**
 627  * of_get_flat_dt_root - find the root node in the flat blob
 628  */
 629 unsigned long __init of_get_flat_dt_root(void)
 630 {
 631         unsigned long p = ((unsigned long)initial_boot_params) +
 632                 be32_to_cpu(initial_boot_params->off_dt_struct);
 633
 634         while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
 635                 p += 4;
 636         BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
 637         p += 4;
 638         return ALIGN(p + strlen((char *)p) + 1, 4);
 639 }
 640
 641 /**
 642  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 643  *
 644  * This function can be used within scan_flattened_dt callback to get
 645  * access to properties
 646  */
 647 void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 648                                  unsigned long *size)
 649 {
 650         return of_fdt_get_property(initial_boot_params, node, name, size);
 651 }
 652
 653 /**
 654  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 655  * @node: node to test
 656  * @compat: compatible string to compare with compatible list.
 657  */
 658 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 659 {
 660         return of_fdt_is_compatible(initial_boot_params, node, compat);
 661 }
 662
 663 /**
 664  * of_flat_dt_match - Return true if node matches a list of compatible values
 665  */
 666 int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 667 {
 668         return of_fdt_match(initial_boot_params, node, compat);
 669 }
 670
 671 struct fdt_scan_status {
 672         const char *name;
 673         int namelen;
 674         int depth;
 675         int found;
 676         int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 677         void *data;
 678 };
 679
 680 /**
 681  * fdt_scan_node_by_path - iterator for of_scan_flat_dt_by_path function
 682  */
 683 static int __init fdt_scan_node_by_path(unsigned long node, const char *uname,
 684                                         int depth, void *data)
 685 {
 686         struct fdt_scan_status *st = data;
 687
 688         /*
 689          * if scan at the requested fdt node has been completed,
 690          * return -ENXIO to abort further scanning
 691          */
 692         if (depth <= st->depth)
 693                 return -ENXIO;
 694
 695         /* requested fdt node has been found, so call iterator function */
 696         if (st->found)
 697                 return st->iterator(node, uname, depth, st->data);
 698
 699         /* check if scanning automata is entering next level of fdt nodes */
 700         if (depth == st->depth + 1 &&
 701             strncmp(st->name, uname, st->namelen) == 0 &&
 702             uname[st->namelen] == 0) {
 703                 st->depth += 1;
 704                 if (st->name[st->namelen] == 0) {
 705                         st->found = 1;
 706                 } else {
 707                         const char *next = st->name + st->namelen + 1;
 708                         st->name = next;
 709                         st->namelen = strcspn(next, "/");
 710                 }
 711                 return 0;
 712         }
 713
 714         /* scan next fdt node */
 715         return 0;
 716 }
 717
 718 /**
 719  * of_scan_flat_dt_by_path - scan flattened tree blob and call callback on each
 720  *                           child of the given path.
 721  * @path: path to start searching for children
 722  * @it: callback function
 723  * @data: context data pointer
 724  *
 725  * This function is used to scan the flattened device-tree starting from the
 726  * node given by path. It is used to extract information (like reserved
 727  * memory), which is required on ealy boot before we can unflatten the tree.
 728  */
 729 int __init of_scan_flat_dt_by_path(const char *path,
 730         int (*it)(unsigned long node, const char *name, int depth, void *data),
 731         void *data)
 732 {
 733         struct fdt_scan_status st = {path, 0, -1, 0, it, data};
 734         int ret = 0;
 735
 736         if (initial_boot_params)
 737                 ret = of_scan_flat_dt(fdt_scan_node_by_path, &st);
 738
 739         if (!st.found)
 740                 return -ENOENT;
 741         else if (ret == -ENXIO) /* scan has been completed */
 742                 return 0;
 743         else
 744                 return ret;
 745 }
 746
 747 #ifdef CONFIG_BLK_DEV_INITRD
 748 /**
 749  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 750  * @node: reference to node containing initrd location ('chosen')
 751  */
 752 void __init early_init_dt_check_for_initrd(unsigned long node)
 753 {
 754         unsigned long start, end, len;
 755         __be32 *prop;
 756
 757         pr_debug("Looking for initrd properties... ");
 758
 759         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 760         if (!prop)
 761                 return;
 762         start = of_read_ulong(prop, len/4);
 763
 764         prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 765         if (!prop)
 766                 return;
 767         end = of_read_ulong(prop, len/4);
 768
 769         early_init_dt_setup_initrd_arch(start, end);
 770         pr_debug("initrd_start=0x%lx  initrd_end=0x%lx\n", start, end);
 771 }
 772 #else
 773 inline void early_init_dt_check_for_initrd(unsigned long node)
 774 {
 775 }
 776 #endif /* CONFIG_BLK_DEV_INITRD */
 777
 778 /**
 779  * early_init_dt_scan_root - fetch the top level address and size cells
 780  */
 781 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 782                                    int depth, void *data)
 783 {
 784         __be32 *prop;
 785
 786         if (depth != 0)
 787                 return 0;
 788
 789         dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 790         dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 791
 792         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 793         if (prop)
 794                 dt_root_size_cells = be32_to_cpup(prop);
 795         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 796
 797         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 798         if (prop)
 799                 dt_root_addr_cells = be32_to_cpup(prop);
 800         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 801
 802         /* break now */
 803         return 1;
 804 }
 805
 806 u64 __init dt_mem_next_cell(int s, __be32 **cellp)
 807 {
 808         __be32 *p = *cellp;
 809
 810         *cellp = p + s;
 811         return of_read_number(p, s);
 812 }
 813
 814 /**
 815  * early_init_dt_scan_memory - Look for an parse memory nodes
 816  */
 817 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 818                                      int depth, void *data)
 819 {
 820         char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 821         __be32 *reg, *endp;
 822         unsigned long l;
 823
 824         /* We are scanning "memory" nodes only */
 825         if (type == NULL) {
 826                 /*
 827                  * The longtrail doesn't have a device_type on the
 828                  * /memory node, so look for the node called /memory@0.
 829                  */
 830                 if (depth != 1 || strcmp(uname, "memory@0") != 0)
 831                         return 0;
 832         } else if (strcmp(type, "memory") != 0)
 833                 return 0;
 834
 835         reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
 836         if (reg == NULL)
 837                 reg = of_get_flat_dt_prop(node, "reg", &l);
 838         if (reg == NULL)
 839                 return 0;
 840
 841         endp = reg + (l / sizeof(__be32));
 842
 843         pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
 844             uname, l, reg[0], reg[1], reg[2], reg[3]);
 845
 846         while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
 847                 u64 base, size;
 848
 849                 base = dt_mem_next_cell(dt_root_addr_cells, &reg);
 850                 size = dt_mem_next_cell(dt_root_size_cells, &reg);
 851
 852                 if (size == 0)
 853                         continue;
 854                 pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
 855                     (unsigned long long)size);
 856
 857                 early_init_dt_add_memory_arch(base, size);
 858         }
 859
 860         return 0;
 861 }
 862
 863 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
 864                                         phys_addr_t size, bool nomap)
 865 {
 866         if (memblock_is_region_reserved(base, size))
 867                 return -EBUSY;
 868         if (nomap)
 869                 return memblock_remove(base, size);
 870         return memblock_reserve(base, size);
 871 }
 872
 873 /*
 874  * Convert configs to something easy to use in C code
 875  */
 876 #if defined(CONFIG_CMDLINE_FORCE)
 877 static const int overwrite_incoming_cmdline = 1;
 878 static const int read_dt_cmdline;
 879 static const int concat_cmdline;
 880 #elif defined(CONFIG_CMDLINE_EXTEND)
 881 static const int overwrite_incoming_cmdline;
 882 static const int read_dt_cmdline = 1;
 883 static const int concat_cmdline = 1;
 884 #else /* CMDLINE_FROM_BOOTLOADER */
 885 static const int overwrite_incoming_cmdline;
 886 static const int read_dt_cmdline = 1;
 887 static const int concat_cmdline;
 888 #endif
 889
 890 #ifdef CONFIG_CMDLINE
 891 static const char *config_cmdline = CONFIG_CMDLINE;
 892 #else
 893 static const char *config_cmdline = "";
 894 #endif
 895
 896 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
 897                                      int depth, void *data)
 898 {
 899         unsigned long l = 0;
 900         char *p = NULL;
 901         char *cmdline = data;
 902
 903         pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
 904
 905         if (depth != 1 || !cmdline ||
 906             (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
 907                 return 0;
 908
 909         early_init_dt_check_for_initrd(node);
 910
 911         /* Put CONFIG_CMDLINE in if forced or if data had nothing in it to start */
 912         if (overwrite_incoming_cmdline || !cmdline[0])
 913                 strlcpy(cmdline, config_cmdline, COMMAND_LINE_SIZE);
 914
 915         /* Retrieve command line unless forcing */
 916         if (read_dt_cmdline)
 917                 p = of_get_flat_dt_prop(node, "bootargs", &l);
 918
 919         if (p != NULL && l > 0) {
 920                 if (concat_cmdline) {
 921                         int cmdline_len;
 922                         int copy_len;
 923                         strlcat(cmdline, " ", COMMAND_LINE_SIZE);
 924                         cmdline_len = strlen(cmdline);
 925                         copy_len = COMMAND_LINE_SIZE - cmdline_len - 1;
 926                         copy_len = min((int)l, copy_len);
 927                         strncpy(cmdline + cmdline_len, p, copy_len);
 928                         cmdline[cmdline_len + copy_len] = '\0';
 929                 } else {
 930                         strlcpy(cmdline, p, min((int)l, COMMAND_LINE_SIZE));
 931                 }
 932         }
 933
 934         pr_debug("Command line is: %s\n", (char*)data);
 935
 936         /* break now */
 937         return 1;
 938 }
 939
 940 #ifdef CONFIG_HAVE_MEMBLOCK
 941 /*
 942  * called from unflatten_device_tree() to bootstrap devicetree itself
 943  * Architectures can override this definition if memblock isn't used
 944  */
 945 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
 946 {
 947         return __va(memblock_alloc(size, align));
 948 }
 949 #else
 950 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
 951                                         phys_addr_t size, bool nomap)
 952 {
 953         pr_err("Reserved memory not supported, ignoring range 0x%llx - 0x%llx%s\n",
 954                   base, size, nomap ? " (nomap)" : "");
 955         return -ENOSYS;
 956 }
 957 #endif
 958
 959 /**
 960  * unflatten_device_tree - create tree of device_nodes from flat blob
 961  *
 962  * unflattens the device-tree passed by the firmware, creating the
 963  * tree of struct device_node. It also fills the "name" and "type"
 964  * pointers of the nodes so the normal device-tree walking functions
 965  * can be used.
 966  */
 967 void __init unflatten_device_tree(void)
 968 {
 969         __unflatten_device_tree(initial_boot_params, &of_allnodes,
 970                                 early_init_dt_alloc_memory_arch);
 971
 972         /* Get pointer to "/chosen" and "/aliasas" nodes for use everywhere */
 973         of_alias_scan(early_init_dt_alloc_memory_arch);
 974 }
 975
 976 #endif /* CONFIG_OF_EARLY_FLATTREE */