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(void **mem, unsigned long size,
 132                                        unsigned long align)
 133 {
 134         void *res;
 135
 136         *mem = PTR_ALIGN(*mem, align);
 137         res = *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 void * unflatten_dt_node(struct boot_param_header *blob,
 153                                 void *mem,
 154                                 void **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(*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 = *p;
 174         l = allocl = strlen(pathp) + 1;
 175         *p = PTR_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                 of_node_init(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         }
 239         /* process properties */
 240         while (1) {
 241                 u32 sz, noff;
 242                 char *pname;
 243
 244                 tag = be32_to_cpup(*p);
 245                 if (tag == OF_DT_NOP) {
 246                         *p += 4;
 247                         continue;
 248                 }
 249                 if (tag != OF_DT_PROP)
 250                         break;
 251                 *p += 4;
 252                 sz = be32_to_cpup(*p);
 253                 noff = be32_to_cpup(*p + 4);
 254                 *p += 8;
 255                 if (be32_to_cpu(blob->version) < 0x10)
 256                         *p = PTR_ALIGN(*p, sz >= 8 ? 8 : 4);
 257
 258                 pname = of_fdt_get_string(blob, noff);
 259                 if (pname == NULL) {
 260                         pr_info("Can't find property name in list !\n");
 261                         break;
 262                 }
 263                 if (strcmp(pname, "name") == 0)
 264                         has_name = 1;
 265                 l = strlen(pname) + 1;
 266                 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
 267                                         __alignof__(struct property));
 268                 if (allnextpp) {
 269                         /* We accept flattened tree phandles either in
 270                          * ePAPR-style "phandle" properties, or the
 271                          * legacy "linux,phandle" properties.  If both
 272                          * appear and have different values, things
 273                          * will get weird.  Don't do that. */
 274                         if ((strcmp(pname, "phandle") == 0) ||
 275                             (strcmp(pname, "linux,phandle") == 0)) {
 276                                 if (np->phandle == 0)
 277                                         np->phandle = be32_to_cpup((__be32*)*p);
 278                         }
 279                         /* And we process the "ibm,phandle" property
 280                          * used in pSeries dynamic device tree
 281                          * stuff */
 282                         if (strcmp(pname, "ibm,phandle") == 0)
 283                                 np->phandle = be32_to_cpup((__be32 *)*p);
 284                         pp->name = pname;
 285                         pp->length = sz;
 286                         pp->value = *p;
 287                         *prev_pp = pp;
 288                         prev_pp = &pp->next;
 289                 }
 290                 *p = PTR_ALIGN((*p) + sz, 4);
 291         }
 292         /* with version 0x10 we may not have the name property, recreate
 293          * it here from the unit name if absent
 294          */
 295         if (!has_name) {
 296                 char *p1 = pathp, *ps = pathp, *pa = NULL;
 297                 int sz;
 298
 299                 while (*p1) {
 300                         if ((*p1) == '@')
 301                                 pa = p1;
 302                         if ((*p1) == '/')
 303                                 ps = p1 + 1;
 304                         p1++;
 305                 }
 306                 if (pa < ps)
 307                         pa = p1;
 308                 sz = (pa - ps) + 1;
 309                 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
 310                                         __alignof__(struct property));
 311                 if (allnextpp) {
 312                         pp->name = "name";
 313                         pp->length = sz;
 314                         pp->value = pp + 1;
 315                         *prev_pp = pp;
 316                         prev_pp = &pp->next;
 317                         memcpy(pp->value, ps, sz - 1);
 318                         ((char *)pp->value)[sz - 1] = 0;
 319                         pr_debug("fixed up name for %s -> %s\n", pathp,
 320                                 (char *)pp->value);
 321                 }
 322         }
 323         if (allnextpp) {
 324                 *prev_pp = NULL;
 325                 np->name = of_get_property(np, "name", NULL);
 326                 np->type = of_get_property(np, "device_type", NULL);
 327
 328                 if (!np->name)
 329                         np->name = "<NULL>";
 330                 if (!np->type)
 331                         np->type = "<NULL>";
 332         }
 333         while (tag == OF_DT_BEGIN_NODE || tag == OF_DT_NOP) {
 334                 if (tag == OF_DT_NOP)
 335                         *p += 4;
 336                 else
 337                         mem = unflatten_dt_node(blob, mem, p, np, allnextpp,
 338                                                 fpsize);
 339                 tag = be32_to_cpup(*p);
 340         }
 341         if (tag != OF_DT_END_NODE) {
 342                 pr_err("Weird tag at end of node: %x\n", tag);
 343                 return mem;
 344         }
 345         *p += 4;
 346         return mem;
 347 }
 348
 349 /**
 350  * __unflatten_device_tree - create tree of device_nodes from flat blob
 351  *
 352  * unflattens a device-tree, creating the
 353  * tree of struct device_node. It also fills the "name" and "type"
 354  * pointers of the nodes so the normal device-tree walking functions
 355  * can be used.
 356  * @blob: The blob to expand
 357  * @mynodes: The device_node tree created by the call
 358  * @dt_alloc: An allocator that provides a virtual address to memory
 359  * for the resulting tree
 360  */
 361 static void __unflatten_device_tree(struct boot_param_header *blob,
 362                              struct device_node **mynodes,
 363                              void * (*dt_alloc)(u64 size, u64 align))
 364 {
 365         unsigned long size;
 366         void *start, *mem;
 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 = ((void *)blob) + be32_to_cpu(blob->off_dt_struct);
 388         size = (unsigned long)unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
 389         size = ALIGN(size, 4);
 390
 391         pr_debug("  size is %lx, allocating...\n", size);
 392
 393         /* Allocate memory for the expanded device tree */
 394         mem = dt_alloc(size + 4, __alignof__(struct device_node));
 395         memset(mem, 0, size);
 396
 397         *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 398
 399         pr_debug("  unflattening %p...\n", mem);
 400
 401         /* Second pass, do actual unflattening */
 402         start = ((void *)blob) + be32_to_cpu(blob->off_dt_struct);
 403         unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
 404         if (be32_to_cpup(start) != OF_DT_END)
 405                 pr_warning("Weird tag at end of tree: %08x\n", be32_to_cpup(start));
 406         if (be32_to_cpup(mem + size) != 0xdeadbeef)
 407                 pr_warning("End of tree marker overwritten: %08x\n",
 408                            be32_to_cpup(mem + size));
 409         *allnextp = NULL;
 410
 411         pr_debug(" <- unflatten_device_tree()\n");
 412 }
 413
 414 static void *kernel_tree_alloc(u64 size, u64 align)
 415 {
 416         return kzalloc(size, GFP_KERNEL);
 417 }
 418
 419 /**
 420  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 421  *
 422  * unflattens the device-tree passed by the firmware, creating the
 423  * tree of struct device_node. It also fills the "name" and "type"
 424  * pointers of the nodes so the normal device-tree walking functions
 425  * can be used.
 426  */
 427 void of_fdt_unflatten_tree(unsigned long *blob,
 428                         struct device_node **mynodes)
 429 {
 430         struct boot_param_header *device_tree =
 431                 (struct boot_param_header *)blob;
 432         __unflatten_device_tree(device_tree, mynodes, &kernel_tree_alloc);
 433 }
 434 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 435
 436 /* Everything below here references initial_boot_params directly. */
 437 int __initdata dt_root_addr_cells;
 438 int __initdata dt_root_size_cells;
 439
 440 struct boot_param_header *initial_boot_params;
 441
 442 #ifdef CONFIG_OF_EARLY_FLATTREE
 443
 444 /**
 445  * res_mem_reserve_reg() - reserve all memory described in 'reg' property
 446  */
 447 static int __init __reserved_mem_reserve_reg(unsigned long node,
 448                                              const char *uname)
 449 {
 450         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 451         phys_addr_t base, size;
 452         unsigned long len;
 453         __be32 *prop;
 454         int nomap, first = 1;
 455
 456         prop = of_get_flat_dt_prop(node, "reg", &len);
 457         if (!prop)
 458                 return -ENOENT;
 459
 460         if (len && len % t_len != 0) {
 461                 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 462                        uname);
 463                 return -EINVAL;
 464         }
 465
 466         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 467
 468         while (len >= t_len) {
 469                 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 470                 size = dt_mem_next_cell(dt_root_size_cells, &prop);
 471
 472                 if (base && size &&
 473                     early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 474                         pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 475                                 uname, &base, (unsigned long)size / SZ_1M);
 476                 else
 477                         pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 478                                 uname, &base, (unsigned long)size / SZ_1M);
 479
 480                 len -= t_len;
 481                 if (first) {
 482                         fdt_reserved_mem_save_node(node, uname, base, size);
 483                         first = 0;
 484                 }
 485         }
 486         return 0;
 487 }
 488
 489 /**
 490  * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 491  * in /reserved-memory matches the values supported by the current implementation,
 492  * also check if ranges property has been provided
 493  */
 494 static int __init __reserved_mem_check_root(unsigned long node)
 495 {
 496         __be32 *prop;
 497
 498         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 499         if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 500                 return -EINVAL;
 501
 502         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 503         if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 504                 return -EINVAL;
 505
 506         prop = of_get_flat_dt_prop(node, "ranges", NULL);
 507         if (!prop)
 508                 return -EINVAL;
 509         return 0;
 510 }
 511
 512 /**
 513  * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 514  */
 515 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 516                                           int depth, void *data)
 517 {
 518         static int found;
 519         const char *status;
 520         int err;
 521
 522         if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 523                 if (__reserved_mem_check_root(node) != 0) {
 524                         pr_err("Reserved memory: unsupported node format, ignoring\n");
 525                         /* break scan */
 526                         return 1;
 527                 }
 528                 found = 1;
 529                 /* scan next node */
 530                 return 0;
 531         } else if (!found) {
 532                 /* scan next node */
 533                 return 0;
 534         } else if (found && depth < 2) {
 535                 /* scanning of /reserved-memory has been finished */
 536                 return 1;
 537         }
 538
 539         status = of_get_flat_dt_prop(node, "status", NULL);
 540         if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
 541                 return 0;
 542
 543         err = __reserved_mem_reserve_reg(node, uname);
 544         if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 545                 fdt_reserved_mem_save_node(node, uname, 0, 0);
 546
 547         /* scan next node */
 548         return 0;
 549 }
 550
 551 /**
 552  * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 553  *
 554  * This function grabs memory from early allocator for device exclusive use
 555  * defined in device tree structures. It should be called by arch specific code
 556  * once the early allocator (i.e. memblock) has been fully activated.
 557  */
 558 void __init early_init_fdt_scan_reserved_mem(void)
 559 {
 560         if (!initial_boot_params)
 561                 return;
 562
 563         of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 564         fdt_init_reserved_mem();
 565 }
 566
 567 /**
 568  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 569  * @it: callback function
 570  * @data: context data pointer
 571  *
 572  * This function is used to scan the flattened device-tree, it is
 573  * used to extract the memory information at boot before we can
 574  * unflatten the tree
 575  */
 576 int __init of_scan_flat_dt(int (*it)(unsigned long node,
 577                                      const char *uname, int depth,
 578                                      void *data),
 579                            void *data)
 580 {
 581         unsigned long p = ((unsigned long)initial_boot_params) +
 582                 be32_to_cpu(initial_boot_params->off_dt_struct);
 583         int rc = 0;
 584         int depth = -1;
 585
 586         do {
 587                 u32 tag = be32_to_cpup((__be32 *)p);
 588                 const char *pathp;
 589
 590                 p += 4;
 591                 if (tag == OF_DT_END_NODE) {
 592                         depth--;
 593                         continue;
 594                 }
 595                 if (tag == OF_DT_NOP)
 596                         continue;
 597                 if (tag == OF_DT_END)
 598                         break;
 599                 if (tag == OF_DT_PROP) {
 600                         u32 sz = be32_to_cpup((__be32 *)p);
 601                         p += 8;
 602                         if (be32_to_cpu(initial_boot_params->version) < 0x10)
 603                                 p = ALIGN(p, sz >= 8 ? 8 : 4);
 604                         p += sz;
 605                         p = ALIGN(p, 4);
 606                         continue;
 607                 }
 608                 if (tag != OF_DT_BEGIN_NODE) {
 609                         pr_err("Invalid tag %x in flat device tree!\n", tag);
 610                         return -EINVAL;
 611                 }
 612                 depth++;
 613                 pathp = (char *)p;
 614                 p = ALIGN(p + strlen(pathp) + 1, 4);
 615                 if (*pathp == '/')
 616                         pathp = kbasename(pathp);
 617                 rc = it(p, pathp, depth, data);
 618                 if (rc != 0)
 619                         break;
 620         } while (1);
 621
 622         return rc;
 623 }
 624
 625 /**
 626  * of_get_flat_dt_root - find the root node in the flat blob
 627  */
 628 unsigned long __init of_get_flat_dt_root(void)
 629 {
 630         unsigned long p = ((unsigned long)initial_boot_params) +
 631                 be32_to_cpu(initial_boot_params->off_dt_struct);
 632
 633         while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
 634                 p += 4;
 635         BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
 636         p += 4;
 637         return ALIGN(p + strlen((char *)p) + 1, 4);
 638 }
 639
 640 /**
 641  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 642  *
 643  * This function can be used within scan_flattened_dt callback to get
 644  * access to properties
 645  */
 646 void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 647                                  unsigned long *size)
 648 {
 649         return of_fdt_get_property(initial_boot_params, node, name, size);
 650 }
 651
 652 /**
 653  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 654  * @node: node to test
 655  * @compat: compatible string to compare with compatible list.
 656  */
 657 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 658 {
 659         return of_fdt_is_compatible(initial_boot_params, node, compat);
 660 }
 661
 662 /**
 663  * of_flat_dt_match - Return true if node matches a list of compatible values
 664  */
 665 int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 666 {
 667         return of_fdt_match(initial_boot_params, node, compat);
 668 }
 669
 670 struct fdt_scan_status {
 671         const char *name;
 672         int namelen;
 673         int depth;
 674         int found;
 675         int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 676         void *data;
 677 };
 678
 679 /**
 680  * fdt_scan_node_by_path - iterator for of_scan_flat_dt_by_path function
 681  */
 682 static int __init fdt_scan_node_by_path(unsigned long node, const char *uname,
 683                                         int depth, void *data)
 684 {
 685         struct fdt_scan_status *st = data;
 686
 687         /*
 688          * if scan at the requested fdt node has been completed,
 689          * return -ENXIO to abort further scanning
 690          */
 691         if (depth <= st->depth)
 692                 return -ENXIO;
 693
 694         /* requested fdt node has been found, so call iterator function */
 695         if (st->found)
 696                 return st->iterator(node, uname, depth, st->data);
 697
 698         /* check if scanning automata is entering next level of fdt nodes */
 699         if (depth == st->depth + 1 &&
 700             strncmp(st->name, uname, st->namelen) == 0 &&
 701             uname[st->namelen] == 0) {
 702                 st->depth += 1;
 703                 if (st->name[st->namelen] == 0) {
 704                         st->found = 1;
 705                 } else {
 706                         const char *next = st->name + st->namelen + 1;
 707                         st->name = next;
 708                         st->namelen = strcspn(next, "/");
 709                 }
 710                 return 0;
 711         }
 712
 713         /* scan next fdt node */
 714         return 0;
 715 }
 716
 717 /**
 718  * of_scan_flat_dt_by_path - scan flattened tree blob and call callback on each
 719  *                           child of the given path.
 720  * @path: path to start searching for children
 721  * @it: callback function
 722  * @data: context data pointer
 723  *
 724  * This function is used to scan the flattened device-tree starting from the
 725  * node given by path. It is used to extract information (like reserved
 726  * memory), which is required on ealy boot before we can unflatten the tree.
 727  */
 728 int __init of_scan_flat_dt_by_path(const char *path,
 729         int (*it)(unsigned long node, const char *name, int depth, void *data),
 730         void *data)
 731 {
 732         struct fdt_scan_status st = {path, 0, -1, 0, it, data};
 733         int ret = 0;
 734
 735         if (initial_boot_params)
 736                 ret = of_scan_flat_dt(fdt_scan_node_by_path, &st);
 737
 738         if (!st.found)
 739                 return -ENOENT;
 740         else if (ret == -ENXIO) /* scan has been completed */
 741                 return 0;
 742         else
 743                 return ret;
 744 }
 745
 746 const char * __init of_flat_dt_get_machine_name(void)
 747 {
 748         const char *name;
 749         unsigned long dt_root = of_get_flat_dt_root();
 750
 751         name = of_get_flat_dt_prop(dt_root, "model", NULL);
 752         if (!name)
 753                 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 754         return name;
 755 }
 756
 757 /**
 758  * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 759  *
 760  * @default_match: A machine specific ptr to return in case of no match.
 761  * @get_next_compat: callback function to return next compatible match table.
 762  *
 763  * Iterate through machine match tables to find the best match for the machine
 764  * compatible string in the FDT.
 765  */
 766 const void * __init of_flat_dt_match_machine(const void *default_match,
 767                 const void * (*get_next_compat)(const char * const**))
 768 {
 769         const void *data = NULL;
 770         const void *best_data = default_match;
 771         const char *const *compat;
 772         unsigned long dt_root;
 773         unsigned int best_score = ~1, score = 0;
 774
 775         dt_root = of_get_flat_dt_root();
 776         while ((data = get_next_compat(&compat))) {
 777                 score = of_flat_dt_match(dt_root, compat);
 778                 if (score > 0 && score < best_score) {
 779                         best_data = data;
 780                         best_score = score;
 781                 }
 782         }
 783         if (!best_data) {
 784                 const char *prop;
 785                 long size;
 786
 787                 pr_err("\n unrecognized device tree list:\n[ ");
 788
 789                 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 790                 if (prop) {
 791                         while (size > 0) {
 792                                 printk("'%s' ", prop);
 793                                 size -= strlen(prop) + 1;
 794                                 prop += strlen(prop) + 1;
 795                         }
 796                 }
 797                 printk("]\n\n");
 798                 return NULL;
 799         }
 800
 801         pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 802
 803         return best_data;
 804 }
 805
 806 #ifdef CONFIG_BLK_DEV_INITRD
 807 /**
 808  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 809  * @node: reference to node containing initrd location ('chosen')
 810  */
 811 static void __init early_init_dt_check_for_initrd(unsigned long node)
 812 {
 813         u64 start, end;
 814         unsigned long len;
 815         __be32 *prop;
 816
 817         pr_debug("Looking for initrd properties... ");
 818
 819         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 820         if (!prop)
 821                 return;
 822         start = of_read_number(prop, len/4);
 823
 824         prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 825         if (!prop)
 826                 return;
 827         end = of_read_number(prop, len/4);
 828
 829         initrd_start = (unsigned long)__va(start);
 830         initrd_end = (unsigned long)__va(end);
 831         initrd_below_start_ok = 1;
 832
 833         pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 834                  (unsigned long long)start, (unsigned long long)end);
 835 }
 836 #else
 837 static inline void early_init_dt_check_for_initrd(unsigned long node)
 838 {
 839 }
 840 #endif /* CONFIG_BLK_DEV_INITRD */
 841
 842 /**
 843  * early_init_dt_scan_root - fetch the top level address and size cells
 844  */
 845 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 846                                    int depth, void *data)
 847 {
 848         __be32 *prop;
 849
 850         if (depth != 0)
 851                 return 0;
 852
 853         dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 854         dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 855
 856         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 857         if (prop)
 858                 dt_root_size_cells = be32_to_cpup(prop);
 859         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 860
 861         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 862         if (prop)
 863                 dt_root_addr_cells = be32_to_cpup(prop);
 864         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 865
 866         /* break now */
 867         return 1;
 868 }
 869
 870 u64 __init dt_mem_next_cell(int s, __be32 **cellp)
 871 {
 872         __be32 *p = *cellp;
 873
 874         *cellp = p + s;
 875         return of_read_number(p, s);
 876 }
 877
 878 /**
 879  * early_init_dt_scan_memory - Look for an parse memory nodes
 880  */
 881 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 882                                      int depth, void *data)
 883 {
 884         char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 885         __be32 *reg, *endp;
 886         unsigned long l;
 887
 888         /* We are scanning "memory" nodes only */
 889         if (type == NULL) {
 890                 /*
 891                  * The longtrail doesn't have a device_type on the
 892                  * /memory node, so look for the node called /memory@0.
 893                  */
 894                 if (depth != 1 || strcmp(uname, "memory@0") != 0)
 895                         return 0;
 896         } else if (strcmp(type, "memory") != 0)
 897                 return 0;
 898
 899         reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
 900         if (reg == NULL)
 901                 reg = of_get_flat_dt_prop(node, "reg", &l);
 902         if (reg == NULL)
 903                 return 0;
 904
 905         endp = reg + (l / sizeof(__be32));
 906
 907         pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
 908             uname, l, reg[0], reg[1], reg[2], reg[3]);
 909
 910         while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
 911                 u64 base, size;
 912
 913                 base = dt_mem_next_cell(dt_root_addr_cells, &reg);
 914                 size = dt_mem_next_cell(dt_root_size_cells, &reg);
 915
 916                 if (size == 0)
 917                         continue;
 918                 pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
 919                     (unsigned long long)size);
 920
 921                 early_init_dt_add_memory_arch(base, size);
 922         }
 923
 924         return 0;
 925 }
 926
 927 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
 928                                      int depth, void *data)
 929 {
 930         unsigned long l;
 931         char *p;
 932
 933         pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
 934
 935         if (depth != 1 || !data ||
 936             (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
 937                 return 0;
 938
 939         early_init_dt_check_for_initrd(node);
 940
 941         /* Retrieve command line */
 942         p = of_get_flat_dt_prop(node, "bootargs", &l);
 943         if (p != NULL && l > 0)
 944                 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
 945
 946         /*
 947          * CONFIG_CMDLINE is meant to be a default in case nothing else
 948          * managed to set the command line, unless CONFIG_CMDLINE_FORCE
 949          * is set in which case we override whatever was found earlier.
 950          */
 951 #ifdef CONFIG_CMDLINE
 952 #ifndef CONFIG_CMDLINE_FORCE
 953         if (!((char *)data)[0])
 954 #endif
 955                 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 956 #endif /* CONFIG_CMDLINE */
 957
 958         pr_debug("Command line is: %s\n", (char*)data);
 959
 960         /* break now */
 961         return 1;
 962 }
 963
 964 #ifdef CONFIG_HAVE_MEMBLOCK
 965 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
 966 {
 967         const u64 phys_offset = __pa(PAGE_OFFSET);
 968         base &= PAGE_MASK;
 969         size &= PAGE_MASK;
 970         if (base + size < phys_offset) {
 971                 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
 972                            base, base + size);
 973                 return;
 974         }
 975         if (base < phys_offset) {
 976                 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
 977                            base, phys_offset);
 978                 size -= phys_offset - base;
 979                 base = phys_offset;
 980         }
 981         memblock_add(base, size);
 982 }
 983
 984 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
 985                                         phys_addr_t size, bool nomap)
 986 {
 987         if (memblock_is_region_reserved(base, size))
 988                 return -EBUSY;
 989         if (nomap)
 990                 return memblock_remove(base, size);
 991         return memblock_reserve(base, size);
 992 }
 993
 994 /*
 995  * called from unflatten_device_tree() to bootstrap devicetree itself
 996  * Architectures can override this definition if memblock isn't used
 997  */
 998 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
 999 {
1000         return __va(memblock_alloc(size, align));
1001 }
1002 #else
1003 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1004                                         phys_addr_t size, bool nomap)
1005 {
1006         pr_err("Reserved memory not supported, ignoring range 0x%llx - 0x%llx%s\n",
1007                   base, size, nomap ? " (nomap)" : "");
1008         return -ENOSYS;
1009 }
1010 #endif
1011
1012 bool __init early_init_dt_scan(void *params)
1013 {
1014         if (!params)
1015                 return false;
1016
1017         /* Setup flat device-tree pointer */
1018         initial_boot_params = params;
1019
1020         /* check device tree validity */
1021         if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) {
1022                 initial_boot_params = NULL;
1023                 return false;
1024         }
1025
1026         /* Retrieve various information from the /chosen node */
1027         of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1028
1029         /* Initialize {size,address}-cells info */
1030         of_scan_flat_dt(early_init_dt_scan_root, NULL);
1031
1032         /* Setup memory, calling early_init_dt_add_memory_arch */
1033         of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1034
1035         return true;
1036 }
1037
1038 /**
1039  * unflatten_device_tree - create tree of device_nodes from flat blob
1040  *
1041  * unflattens the device-tree passed by the firmware, creating the
1042  * tree of struct device_node. It also fills the "name" and "type"
1043  * pointers of the nodes so the normal device-tree walking functions
1044  * can be used.
1045  */
1046 void __init unflatten_device_tree(void)
1047 {
1048         __unflatten_device_tree(initial_boot_params, &of_allnodes,
1049                                 early_init_dt_alloc_memory_arch);
1050
1051         /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1052         of_alias_scan(early_init_dt_alloc_memory_arch);
1053 }
1054
1055 /**
1056  * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1057  *
1058  * Copies and unflattens the device-tree passed by the firmware, creating the
1059  * tree of struct device_node. It also fills the "name" and "type"
1060  * pointers of the nodes so the normal device-tree walking functions
1061  * can be used. This should only be used when the FDT memory has not been
1062  * reserved such is the case when the FDT is built-in to the kernel init
1063  * section. If the FDT memory is reserved already then unflatten_device_tree
1064  * should be used instead.
1065  */
1066 void __init unflatten_and_copy_device_tree(void)
1067 {
1068         int size;
1069         void *dt;
1070
1071         if (!initial_boot_params) {
1072                 pr_warn("No valid device tree found, continuing without\n");
1073                 return;
1074         }
1075
1076         size = __be32_to_cpu(initial_boot_params->totalsize);
1077         dt = early_init_dt_alloc_memory_arch(size,
1078                 __alignof__(struct boot_param_header));
1079
1080         if (dt) {
1081                 memcpy(dt, initial_boot_params, size);
1082                 initial_boot_params = dt;
1083         }
1084         unflatten_device_tree();
1085 }
1086
1087 #endif /* CONFIG_OF_EARLY_FLATTREE */