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/crc32.h>
  13 #include <linux/kernel.h>
  14 #include <linux/initrd.h>
  15 #include <linux/memblock.h>
  16 #include <linux/mutex.h>
  17 #include <linux/of.h>
  18 #include <linux/of_fdt.h>
  19 #include <linux/of_reserved_mem.h>
  20 #include <linux/sizes.h>
  21 #include <linux/string.h>
  22 #include <linux/errno.h>
  23 #include <linux/slab.h>
  24 #include <linux/libfdt.h>
  25 #include <linux/debugfs.h>
  26 #include <linux/serial_core.h>
  27 #include <linux/sysfs.h>
  28
  29 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  30 #include <asm/page.h>
  31
  32 /*
  33  * of_fdt_limit_memory - limit the number of regions in the /memory node
  34  * @limit: maximum entries
  35  *
  36  * Adjust the flattened device tree to have at most 'limit' number of
  37  * memory entries in the /memory node. This function may be called
  38  * any time after initial_boot_param is set.
  39  */
  40 void of_fdt_limit_memory(int limit)
  41 {
  42         int memory;
  43         int len;
  44         const void *val;
  45         int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
  46         int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
  47         const uint32_t *addr_prop;
  48         const uint32_t *size_prop;
  49         int root_offset;
  50         int cell_size;
  51
  52         root_offset = fdt_path_offset(initial_boot_params, "/");
  53         if (root_offset < 0)
  54                 return;
  55
  56         addr_prop = fdt_getprop(initial_boot_params, root_offset,
  57                                 "#address-cells", NULL);
  58         if (addr_prop)
  59                 nr_address_cells = fdt32_to_cpu(*addr_prop);
  60
  61         size_prop = fdt_getprop(initial_boot_params, root_offset,
  62                                 "#size-cells", NULL);
  63         if (size_prop)
  64                 nr_size_cells = fdt32_to_cpu(*size_prop);
  65
  66         cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
  67
  68         memory = fdt_path_offset(initial_boot_params, "/memory");
  69         if (memory > 0) {
  70                 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
  71                 if (len > limit*cell_size) {
  72                         len = limit*cell_size;
  73                         pr_debug("Limiting number of entries to %d\n", limit);
  74                         fdt_setprop(initial_boot_params, memory, "reg", val,
  75                                         len);
  76                 }
  77         }
  78 }
  79
  80 /**
  81  * of_fdt_is_compatible - Return true if given node from the given blob has
  82  * compat in its compatible list
  83  * @blob: A device tree blob
  84  * @node: node to test
  85  * @compat: compatible string to compare with compatible list.
  86  *
  87  * On match, returns a non-zero value with smaller values returned for more
  88  * specific compatible values.
  89  */
  90 int of_fdt_is_compatible(const void *blob,
  91                       unsigned long node, const char *compat)
  92 {
  93         const char *cp;
  94         int cplen;
  95         unsigned long l, score = 0;
  96
  97         cp = fdt_getprop(blob, node, "compatible", &cplen);
  98         if (cp == NULL)
  99                 return 0;
 100         while (cplen > 0) {
 101                 score++;
 102                 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 103                         return score;
 104                 l = strlen(cp) + 1;
 105                 cp += l;
 106                 cplen -= l;
 107         }
 108
 109         return 0;
 110 }
 111
 112 /**
 113  * of_fdt_is_big_endian - Return true if given node needs BE MMIO accesses
 114  * @blob: A device tree blob
 115  * @node: node to test
 116  *
 117  * Returns true if the node has a "big-endian" property, or if the kernel
 118  * was compiled for BE *and* the node has a "native-endian" property.
 119  * Returns false otherwise.
 120  */
 121 bool of_fdt_is_big_endian(const void *blob, unsigned long node)
 122 {
 123         if (fdt_getprop(blob, node, "big-endian", NULL))
 124                 return true;
 125         if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
 126             fdt_getprop(blob, node, "native-endian", NULL))
 127                 return true;
 128         return false;
 129 }
 130
 131 /**
 132  * of_fdt_match - Return true if node matches a list of compatible values
 133  */
 134 int of_fdt_match(const void *blob, unsigned long node,
 135                  const char *const *compat)
 136 {
 137         unsigned int tmp, score = 0;
 138
 139         if (!compat)
 140                 return 0;
 141
 142         while (*compat) {
 143                 tmp = of_fdt_is_compatible(blob, node, *compat);
 144                 if (tmp && (score == 0 || (tmp < score)))
 145                         score = tmp;
 146                 compat++;
 147         }
 148
 149         return score;
 150 }
 151
 152 static void *unflatten_dt_alloc(void **mem, unsigned long size,
 153                                        unsigned long align)
 154 {
 155         void *res;
 156
 157         *mem = PTR_ALIGN(*mem, align);
 158         res = *mem;
 159         *mem += size;
 160
 161         return res;
 162 }
 163
 164 static void populate_properties(const void *blob,
 165                                 int offset,
 166                                 void **mem,
 167                                 struct device_node *np,
 168                                 const char *nodename,
 169                                 bool dryrun)
 170 {
 171         struct property *pp, **pprev = NULL;
 172         int cur;
 173         bool has_name = false;
 174
 175         pprev = &np->properties;
 176         for (cur = fdt_first_property_offset(blob, offset);
 177              cur >= 0;
 178              cur = fdt_next_property_offset(blob, cur)) {
 179                 const __be32 *val;
 180                 const char *pname;
 181                 u32 sz;
 182
 183                 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
 184                 if (!val) {
 185                         pr_warn("%s: Cannot locate property at 0x%x\n",
 186                                 __func__, cur);
 187                         continue;
 188                 }
 189
 190                 if (!pname) {
 191                         pr_warn("%s: Cannot find property name at 0x%x\n",
 192                                 __func__, cur);
 193                         continue;
 194                 }
 195
 196                 if (!strcmp(pname, "name"))
 197                         has_name = true;
 198
 199                 pp = unflatten_dt_alloc(mem, sizeof(struct property),
 200                                         __alignof__(struct property));
 201                 if (dryrun)
 202                         continue;
 203
 204                 /* We accept flattened tree phandles either in
 205                  * ePAPR-style "phandle" properties, or the
 206                  * legacy "linux,phandle" properties.  If both
 207                  * appear and have different values, things
 208                  * will get weird. Don't do that.
 209                  */
 210                 if (!strcmp(pname, "phandle") ||
 211                     !strcmp(pname, "linux,phandle")) {
 212                         if (!np->phandle)
 213                                 np->phandle = be32_to_cpup(val);
 214                 }
 215
 216                 /* And we process the "ibm,phandle" property
 217                  * used in pSeries dynamic device tree
 218                  * stuff
 219                  */
 220                 if (!strcmp(pname, "ibm,phandle"))
 221                         np->phandle = be32_to_cpup(val);
 222
 223                 pp->name   = (char *)pname;
 224                 pp->length = sz;
 225                 pp->value  = (__be32 *)val;
 226                 *pprev     = pp;
 227                 pprev      = &pp->next;
 228         }
 229
 230         /* With version 0x10 we may not have the name property,
 231          * recreate it here from the unit name if absent
 232          */
 233         if (!has_name) {
 234                 const char *p = nodename, *ps = p, *pa = NULL;
 235                 int len;
 236
 237                 while (*p) {
 238                         if ((*p) == '@')
 239                                 pa = p;
 240                         else if ((*p) == '/')
 241                                 ps = p + 1;
 242                         p++;
 243                 }
 244
 245                 if (pa < ps)
 246                         pa = p;
 247                 len = (pa - ps) + 1;
 248                 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
 249                                         __alignof__(struct property));
 250                 if (!dryrun) {
 251                         pp->name   = "name";
 252                         pp->length = len;
 253                         pp->value  = pp + 1;
 254                         *pprev     = pp;
 255                         pprev      = &pp->next;
 256                         memcpy(pp->value, ps, len - 1);
 257                         ((char *)pp->value)[len - 1] = 0;
 258                         pr_debug("fixed up name for %s -> %s\n",
 259                                  nodename, (char *)pp->value);
 260                 }
 261         }
 262
 263         if (!dryrun)
 264                 *pprev = NULL;
 265 }
 266
 267 static unsigned int populate_node(const void *blob,
 268                                   int offset,
 269                                   void **mem,
 270                                   struct device_node *dad,
 271                                   unsigned int fpsize,
 272                                   struct device_node **pnp,
 273                                   bool dryrun)
 274 {
 275         struct device_node *np;
 276         const char *pathp;
 277         unsigned int l, allocl;
 278         int new_format = 0;
 279
 280         pathp = fdt_get_name(blob, offset, &l);
 281         if (!pathp) {
 282                 *pnp = NULL;
 283                 return 0;
 284         }
 285
 286         allocl = ++l;
 287
 288         /* version 0x10 has a more compact unit name here instead of the full
 289          * path. we accumulate the full path size using "fpsize", we'll rebuild
 290          * it later. We detect this because the first character of the name is
 291          * not '/'.
 292          */
 293         if ((*pathp) != '/') {
 294                 new_format = 1;
 295                 if (fpsize == 0) {
 296                         /* root node: special case. fpsize accounts for path
 297                          * plus terminating zero. root node only has '/', so
 298                          * fpsize should be 2, but we want to avoid the first
 299                          * level nodes to have two '/' so we use fpsize 1 here
 300                          */
 301                         fpsize = 1;
 302                         allocl = 2;
 303                         l = 1;
 304                         pathp = "";
 305                 } else {
 306                         /* account for '/' and path size minus terminal 0
 307                          * already in 'l'
 308                          */
 309                         fpsize += l;
 310                         allocl = fpsize;
 311                 }
 312         }
 313
 314         np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
 315                                 __alignof__(struct device_node));
 316         if (!dryrun) {
 317                 char *fn;
 318                 of_node_init(np);
 319                 np->full_name = fn = ((char *)np) + sizeof(*np);
 320                 if (new_format) {
 321                         /* rebuild full path for new format */
 322                         if (dad && dad->parent) {
 323                                 strcpy(fn, dad->full_name);
 324 #ifdef DEBUG
 325                                 if ((strlen(fn) + l + 1) != allocl) {
 326                                         pr_debug("%s: p: %d, l: %d, a: %d\n",
 327                                                 pathp, (int)strlen(fn),
 328                                                 l, allocl);
 329                                 }
 330 #endif
 331                                 fn += strlen(fn);
 332                         }
 333                         *(fn++) = '/';
 334                 }
 335                 memcpy(fn, pathp, l);
 336
 337                 if (dad != NULL) {
 338                         np->parent = dad;
 339                         np->sibling = dad->child;
 340                         dad->child = np;
 341                 }
 342         }
 343
 344         populate_properties(blob, offset, mem, np, pathp, dryrun);
 345         if (!dryrun) {
 346                 np->name = of_get_property(np, "name", NULL);
 347                 np->type = of_get_property(np, "device_type", NULL);
 348
 349                 if (!np->name)
 350                         np->name = "<NULL>";
 351                 if (!np->type)
 352                         np->type = "<NULL>";
 353         }
 354
 355         *pnp = np;
 356         return fpsize;
 357 }
 358
 359 static void reverse_nodes(struct device_node *parent)
 360 {
 361         struct device_node *child, *next;
 362
 363         /* In-depth first */
 364         child = parent->child;
 365         while (child) {
 366                 reverse_nodes(child);
 367
 368                 child = child->sibling;
 369         }
 370
 371         /* Reverse the nodes in the child list */
 372         child = parent->child;
 373         parent->child = NULL;
 374         while (child) {
 375                 next = child->sibling;
 376
 377                 child->sibling = parent->child;
 378                 parent->child = child;
 379                 child = next;
 380         }
 381 }
 382
 383 /**
 384  * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
 385  * @blob: The parent device tree blob
 386  * @mem: Memory chunk to use for allocating device nodes and properties
 387  * @dad: Parent struct device_node
 388  * @nodepp: The device_node tree created by the call
 389  *
 390  * It returns the size of unflattened device tree or error code
 391  */
 392 static int unflatten_dt_nodes(const void *blob,
 393                               void *mem,
 394                               struct device_node *dad,
 395                               struct device_node **nodepp)
 396 {
 397         struct device_node *root;
 398         int offset = 0, depth = 0;
 399 #define FDT_MAX_DEPTH   64
 400         unsigned int fpsizes[FDT_MAX_DEPTH];
 401         struct device_node *nps[FDT_MAX_DEPTH];
 402         void *base = mem;
 403         bool dryrun = !base;
 404
 405         if (nodepp)
 406                 *nodepp = NULL;
 407
 408         root = dad;
 409         fpsizes[depth] = dad ? strlen(of_node_full_name(dad)) : 0;
 410         nps[depth] = dad;
 411         for (offset = 0;
 412              offset >= 0 && depth >= 0;
 413              offset = fdt_next_node(blob, offset, &depth)) {
 414                 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
 415                         continue;
 416
 417                 fpsizes[depth+1] = populate_node(blob, offset, &mem,
 418                                                  nps[depth],
 419                                                  fpsizes[depth],
 420                                                  &nps[depth+1], dryrun);
 421                 if (!fpsizes[depth+1])
 422                         return mem - base;
 423
 424                 if (!dryrun && nodepp && !*nodepp)
 425                         *nodepp = nps[depth+1];
 426                 if (!dryrun && !root)
 427                         root = nps[depth+1];
 428         }
 429
 430         if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 431                 pr_err("%s: Error %d processing FDT\n", __func__, offset);
 432                 return -EINVAL;
 433         }
 434
 435         /*
 436          * Reverse the child list. Some drivers assumes node order matches .dts
 437          * node order
 438          */
 439         if (!dryrun)
 440                 reverse_nodes(root);
 441
 442         return mem - base;
 443 }
 444
 445 /**
 446  * __unflatten_device_tree - create tree of device_nodes from flat blob
 447  *
 448  * unflattens a device-tree, creating the
 449  * tree of struct device_node. It also fills the "name" and "type"
 450  * pointers of the nodes so the normal device-tree walking functions
 451  * can be used.
 452  * @blob: The blob to expand
 453  * @dad: Parent device node
 454  * @mynodes: The device_node tree created by the call
 455  * @dt_alloc: An allocator that provides a virtual address to memory
 456  * for the resulting tree
 457  *
 458  * Returns NULL on failure or the memory chunk containing the unflattened
 459  * device tree on success.
 460  */
 461 static void *__unflatten_device_tree(const void *blob,
 462                                      struct device_node *dad,
 463                                      struct device_node **mynodes,
 464                                      void *(*dt_alloc)(u64 size, u64 align))
 465 {
 466         int size;
 467         void *mem;
 468
 469         pr_debug(" -> unflatten_device_tree()\n");
 470
 471         if (!blob) {
 472                 pr_debug("No device tree pointer\n");
 473                 return NULL;
 474         }
 475
 476         pr_debug("Unflattening device tree:\n");
 477         pr_debug("magic: %08x\n", fdt_magic(blob));
 478         pr_debug("size: %08x\n", fdt_totalsize(blob));
 479         pr_debug("version: %08x\n", fdt_version(blob));
 480
 481         if (fdt_check_header(blob)) {
 482                 pr_err("Invalid device tree blob header\n");
 483                 return NULL;
 484         }
 485
 486         /* First pass, scan for size */
 487         size = unflatten_dt_nodes(blob, NULL, dad, NULL);
 488         if (size < 0)
 489                 return NULL;
 490
 491         size = ALIGN(size, 4);
 492         pr_debug("  size is %d, allocating...\n", size);
 493
 494         /* Allocate memory for the expanded device tree */
 495         mem = dt_alloc(size + 4, __alignof__(struct device_node));
 496         memset(mem, 0, size);
 497
 498         *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 499
 500         pr_debug("  unflattening %p...\n", mem);
 501
 502         /* Second pass, do actual unflattening */
 503         unflatten_dt_nodes(blob, mem, dad, mynodes);
 504         if (be32_to_cpup(mem + size) != 0xdeadbeef)
 505                 pr_warning("End of tree marker overwritten: %08x\n",
 506                            be32_to_cpup(mem + size));
 507
 508         pr_debug(" <- unflatten_device_tree()\n");
 509         return mem;
 510 }
 511
 512 static void *kernel_tree_alloc(u64 size, u64 align)
 513 {
 514         return kzalloc(size, GFP_KERNEL);
 515 }
 516
 517 static DEFINE_MUTEX(of_fdt_unflatten_mutex);
 518
 519 /**
 520  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 521  * @blob: Flat device tree blob
 522  * @dad: Parent device node
 523  * @mynodes: The device tree created by the call
 524  *
 525  * unflattens the device-tree passed by the firmware, creating the
 526  * tree of struct device_node. It also fills the "name" and "type"
 527  * pointers of the nodes so the normal device-tree walking functions
 528  * can be used.
 529  *
 530  * Returns NULL on failure or the memory chunk containing the unflattened
 531  * device tree on success.
 532  */
 533 void *of_fdt_unflatten_tree(const unsigned long *blob,
 534                             struct device_node *dad,
 535                             struct device_node **mynodes)
 536 {
 537         void *mem;
 538
 539         mutex_lock(&of_fdt_unflatten_mutex);
 540         mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc);
 541         mutex_unlock(&of_fdt_unflatten_mutex);
 542
 543         return mem;
 544 }
 545 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 546
 547 /* Everything below here references initial_boot_params directly. */
 548 int __initdata dt_root_addr_cells;
 549 int __initdata dt_root_size_cells;
 550
 551 void *initial_boot_params;
 552
 553 #ifdef CONFIG_OF_EARLY_FLATTREE
 554
 555 static u32 of_fdt_crc32;
 556
 557 /**
 558  * res_mem_reserve_reg() - reserve all memory described in 'reg' property
 559  */
 560 static int __init __reserved_mem_reserve_reg(unsigned long node,
 561                                              const char *uname)
 562 {
 563         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 564         phys_addr_t base, size;
 565         int len;
 566         const __be32 *prop;
 567         int nomap, first = 1;
 568
 569         prop = of_get_flat_dt_prop(node, "reg", &len);
 570         if (!prop)
 571                 return -ENOENT;
 572
 573         if (len && len % t_len != 0) {
 574                 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 575                        uname);
 576                 return -EINVAL;
 577         }
 578
 579         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 580
 581         while (len >= t_len) {
 582                 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 583                 size = dt_mem_next_cell(dt_root_size_cells, &prop);
 584
 585                 if (size &&
 586                     early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 587                         pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 588                                 uname, &base, (unsigned long)size / SZ_1M);
 589                 else
 590                         pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 591                                 uname, &base, (unsigned long)size / SZ_1M);
 592
 593                 len -= t_len;
 594                 if (first) {
 595                         fdt_reserved_mem_save_node(node, uname, base, size);
 596                         first = 0;
 597                 }
 598         }
 599         return 0;
 600 }
 601
 602 /**
 603  * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 604  * in /reserved-memory matches the values supported by the current implementation,
 605  * also check if ranges property has been provided
 606  */
 607 static int __init __reserved_mem_check_root(unsigned long node)
 608 {
 609         const __be32 *prop;
 610
 611         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 612         if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 613                 return -EINVAL;
 614
 615         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 616         if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 617                 return -EINVAL;
 618
 619         prop = of_get_flat_dt_prop(node, "ranges", NULL);
 620         if (!prop)
 621                 return -EINVAL;
 622         return 0;
 623 }
 624
 625 /**
 626  * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 627  */
 628 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 629                                           int depth, void *data)
 630 {
 631         static int found;
 632         const char *status;
 633         int err;
 634
 635         if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 636                 if (__reserved_mem_check_root(node) != 0) {
 637                         pr_err("Reserved memory: unsupported node format, ignoring\n");
 638                         /* break scan */
 639                         return 1;
 640                 }
 641                 found = 1;
 642                 /* scan next node */
 643                 return 0;
 644         } else if (!found) {
 645                 /* scan next node */
 646                 return 0;
 647         } else if (found && depth < 2) {
 648                 /* scanning of /reserved-memory has been finished */
 649                 return 1;
 650         }
 651
 652         status = of_get_flat_dt_prop(node, "status", NULL);
 653         if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
 654                 return 0;
 655
 656         err = __reserved_mem_reserve_reg(node, uname);
 657         if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 658                 fdt_reserved_mem_save_node(node, uname, 0, 0);
 659
 660         /* scan next node */
 661         return 0;
 662 }
 663
 664 /**
 665  * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 666  *
 667  * This function grabs memory from early allocator for device exclusive use
 668  * defined in device tree structures. It should be called by arch specific code
 669  * once the early allocator (i.e. memblock) has been fully activated.
 670  */
 671 void __init early_init_fdt_scan_reserved_mem(void)
 672 {
 673         int n;
 674         u64 base, size;
 675
 676         if (!initial_boot_params)
 677                 return;
 678
 679         /* Process header /memreserve/ fields */
 680         for (n = 0; ; n++) {
 681                 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 682                 if (!size)
 683                         break;
 684                 early_init_dt_reserve_memory_arch(base, size, 0);
 685         }
 686
 687         of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 688         fdt_init_reserved_mem();
 689 }
 690
 691 /**
 692  * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
 693  */
 694 void __init early_init_fdt_reserve_self(void)
 695 {
 696         if (!initial_boot_params)
 697                 return;
 698
 699         /* Reserve the dtb region */
 700         early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
 701                                           fdt_totalsize(initial_boot_params),
 702                                           0);
 703 }
 704
 705 /**
 706  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 707  * @it: callback function
 708  * @data: context data pointer
 709  *
 710  * This function is used to scan the flattened device-tree, it is
 711  * used to extract the memory information at boot before we can
 712  * unflatten the tree
 713  */
 714 int __init of_scan_flat_dt(int (*it)(unsigned long node,
 715                                      const char *uname, int depth,
 716                                      void *data),
 717                            void *data)
 718 {
 719         const void *blob = initial_boot_params;
 720         const char *pathp;
 721         int offset, rc = 0, depth = -1;
 722
 723         for (offset = fdt_next_node(blob, -1, &depth);
 724              offset >= 0 && depth >= 0 && !rc;
 725              offset = fdt_next_node(blob, offset, &depth)) {
 726
 727                 pathp = fdt_get_name(blob, offset, NULL);
 728                 if (*pathp == '/')
 729                         pathp = kbasename(pathp);
 730                 rc = it(offset, pathp, depth, data);
 731         }
 732         return rc;
 733 }
 734
 735 /**
 736  * of_get_flat_dt_root - find the root node in the flat blob
 737  */
 738 unsigned long __init of_get_flat_dt_root(void)
 739 {
 740         return 0;
 741 }
 742
 743 /**
 744  * of_get_flat_dt_size - Return the total size of the FDT
 745  */
 746 int __init of_get_flat_dt_size(void)
 747 {
 748         return fdt_totalsize(initial_boot_params);
 749 }
 750
 751 /**
 752  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 753  *
 754  * This function can be used within scan_flattened_dt callback to get
 755  * access to properties
 756  */
 757 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 758                                        int *size)
 759 {
 760         return fdt_getprop(initial_boot_params, node, name, size);
 761 }
 762
 763 /**
 764  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 765  * @node: node to test
 766  * @compat: compatible string to compare with compatible list.
 767  */
 768 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 769 {
 770         return of_fdt_is_compatible(initial_boot_params, node, compat);
 771 }
 772
 773 /**
 774  * of_flat_dt_match - Return true if node matches a list of compatible values
 775  */
 776 int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 777 {
 778         return of_fdt_match(initial_boot_params, node, compat);
 779 }
 780
 781 struct fdt_scan_status {
 782         const char *name;
 783         int namelen;
 784         int depth;
 785         int found;
 786         int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 787         void *data;
 788 };
 789
 790 const char * __init of_flat_dt_get_machine_name(void)
 791 {
 792         const char *name;
 793         unsigned long dt_root = of_get_flat_dt_root();
 794
 795         name = of_get_flat_dt_prop(dt_root, "model", NULL);
 796         if (!name)
 797                 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 798         return name;
 799 }
 800
 801 /**
 802  * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 803  *
 804  * @default_match: A machine specific ptr to return in case of no match.
 805  * @get_next_compat: callback function to return next compatible match table.
 806  *
 807  * Iterate through machine match tables to find the best match for the machine
 808  * compatible string in the FDT.
 809  */
 810 const void * __init of_flat_dt_match_machine(const void *default_match,
 811                 const void * (*get_next_compat)(const char * const**))
 812 {
 813         const void *data = NULL;
 814         const void *best_data = default_match;
 815         const char *const *compat;
 816         unsigned long dt_root;
 817         unsigned int best_score = ~1, score = 0;
 818
 819         dt_root = of_get_flat_dt_root();
 820         while ((data = get_next_compat(&compat))) {
 821                 score = of_flat_dt_match(dt_root, compat);
 822                 if (score > 0 && score < best_score) {
 823                         best_data = data;
 824                         best_score = score;
 825                 }
 826         }
 827         if (!best_data) {
 828                 const char *prop;
 829                 int size;
 830
 831                 pr_err("\n unrecognized device tree list:\n[ ");
 832
 833                 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 834                 if (prop) {
 835                         while (size > 0) {
 836                                 printk("'%s' ", prop);
 837                                 size -= strlen(prop) + 1;
 838                                 prop += strlen(prop) + 1;
 839                         }
 840                 }
 841                 printk("]\n\n");
 842                 return NULL;
 843         }
 844
 845         pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 846
 847         return best_data;
 848 }
 849
 850 #ifdef CONFIG_BLK_DEV_INITRD
 851 #ifndef __early_init_dt_declare_initrd
 852 static void __early_init_dt_declare_initrd(unsigned long start,
 853                                            unsigned long end)
 854 {
 855         initrd_start = (unsigned long)__va(start);
 856         initrd_end = (unsigned long)__va(end);
 857         initrd_below_start_ok = 1;
 858 }
 859 #endif
 860
 861 /**
 862  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 863  * @node: reference to node containing initrd location ('chosen')
 864  */
 865 static void __init early_init_dt_check_for_initrd(unsigned long node)
 866 {
 867         u64 start, end;
 868         int len;
 869         const __be32 *prop;
 870
 871         pr_debug("Looking for initrd properties... ");
 872
 873         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 874         if (!prop)
 875                 return;
 876         start = of_read_number(prop, len/4);
 877
 878         prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 879         if (!prop)
 880                 return;
 881         end = of_read_number(prop, len/4);
 882
 883         __early_init_dt_declare_initrd(start, end);
 884
 885         pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 886                  (unsigned long long)start, (unsigned long long)end);
 887 }
 888 #else
 889 static inline void early_init_dt_check_for_initrd(unsigned long node)
 890 {
 891 }
 892 #endif /* CONFIG_BLK_DEV_INITRD */
 893
 894 #ifdef CONFIG_SERIAL_EARLYCON
 895
 896 static int __init early_init_dt_scan_chosen_serial(void)
 897 {
 898         int offset;
 899         const char *p, *q, *options = NULL;
 900         int l;
 901         const struct earlycon_id *match;
 902         const void *fdt = initial_boot_params;
 903
 904         offset = fdt_path_offset(fdt, "/chosen");
 905         if (offset < 0)
 906                 offset = fdt_path_offset(fdt, "/chosen@0");
 907         if (offset < 0)
 908                 return -ENOENT;
 909
 910         p = fdt_getprop(fdt, offset, "stdout-path", &l);
 911         if (!p)
 912                 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 913         if (!p || !l)
 914                 return -ENOENT;
 915
 916         q = strchrnul(p, ':');
 917         if (*q != '\0')
 918                 options = q + 1;
 919         l = q - p;
 920
 921         /* Get the node specified by stdout-path */
 922         offset = fdt_path_offset_namelen(fdt, p, l);
 923         if (offset < 0) {
 924                 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
 925                 return 0;
 926         }
 927
 928         for (match = __earlycon_table; match < __earlycon_table_end; match++) {
 929                 if (!match->compatible[0])
 930                         continue;
 931
 932                 if (fdt_node_check_compatible(fdt, offset, match->compatible))
 933                         continue;
 934
 935                 of_setup_earlycon(match, offset, options);
 936                 return 0;
 937         }
 938         return -ENODEV;
 939 }
 940
 941 static int __init setup_of_earlycon(char *buf)
 942 {
 943         if (buf)
 944                 return 0;
 945
 946         return early_init_dt_scan_chosen_serial();
 947 }
 948 early_param("earlycon", setup_of_earlycon);
 949 #endif
 950
 951 /**
 952  * early_init_dt_scan_root - fetch the top level address and size cells
 953  */
 954 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 955                                    int depth, void *data)
 956 {
 957         const __be32 *prop;
 958
 959         if (depth != 0)
 960                 return 0;
 961
 962         dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 963         dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 964
 965         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 966         if (prop)
 967                 dt_root_size_cells = be32_to_cpup(prop);
 968         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 969
 970         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 971         if (prop)
 972                 dt_root_addr_cells = be32_to_cpup(prop);
 973         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 974
 975         /* break now */
 976         return 1;
 977 }
 978
 979 u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
 980 {
 981         const __be32 *p = *cellp;
 982
 983         *cellp = p + s;
 984         return of_read_number(p, s);
 985 }
 986
 987 /**
 988  * early_init_dt_scan_memory - Look for an parse memory nodes
 989  */
 990 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 991                                      int depth, void *data)
 992 {
 993         const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 994         const __be32 *reg, *endp;
 995         int l;
 996
 997         /* We are scanning "memory" nodes only */
 998         if (type == NULL) {
 999                 /*
1000                  * The longtrail doesn't have a device_type on the
1001                  * /memory node, so look for the node called /memory@0.
1002                  */
1003                 if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0)
1004                         return 0;
1005         } else if (strcmp(type, "memory") != 0)
1006                 return 0;
1007
1008         reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1009         if (reg == NULL)
1010                 reg = of_get_flat_dt_prop(node, "reg", &l);
1011         if (reg == NULL)
1012                 return 0;
1013
1014         endp = reg + (l / sizeof(__be32));
1015
1016         pr_debug("memory scan node %s, reg size %d,\n", uname, l);
1017
1018         while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1019                 u64 base, size;
1020
1021                 base = dt_mem_next_cell(dt_root_addr_cells, &reg);
1022                 size = dt_mem_next_cell(dt_root_size_cells, &reg);
1023
1024                 if (size == 0)
1025                         continue;
1026                 pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
1027                     (unsigned long long)size);
1028
1029                 early_init_dt_add_memory_arch(base, size);
1030         }
1031
1032         return 0;
1033 }
1034
1035 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
1036                                      int depth, void *data)
1037 {
1038         int l;
1039         const char *p;
1040
1041         pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
1042
1043         if (depth != 1 || !data ||
1044             (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
1045                 return 0;
1046
1047         early_init_dt_check_for_initrd(node);
1048
1049         /* Retrieve command line */
1050         p = of_get_flat_dt_prop(node, "bootargs", &l);
1051         if (p != NULL && l > 0)
1052                 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
1053
1054         /*
1055          * CONFIG_CMDLINE is meant to be a default in case nothing else
1056          * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1057          * is set in which case we override whatever was found earlier.
1058          */
1059 #ifdef CONFIG_CMDLINE
1060 #if defined(CONFIG_CMDLINE_EXTEND)
1061         strlcat(data, " ", COMMAND_LINE_SIZE);
1062         strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1063 #elif defined(CONFIG_CMDLINE_FORCE)
1064         strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1065 #else
1066         /* No arguments from boot loader, use kernel's  cmdl*/
1067         if (!((char *)data)[0])
1068                 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1069 #endif
1070 #endif /* CONFIG_CMDLINE */
1071
1072         pr_debug("Command line is: %s\n", (char*)data);
1073
1074         /* break now */
1075         return 1;
1076 }
1077
1078 #ifdef CONFIG_HAVE_MEMBLOCK
1079 #ifndef MIN_MEMBLOCK_ADDR
1080 #define MIN_MEMBLOCK_ADDR       __pa(PAGE_OFFSET)
1081 #endif
1082 #ifndef MAX_MEMBLOCK_ADDR
1083 #define MAX_MEMBLOCK_ADDR       ((phys_addr_t)~0)
1084 #endif
1085
1086 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1087 {
1088         const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1089
1090         if (!PAGE_ALIGNED(base)) {
1091                 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1092                         pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1093                                 base, base + size);
1094                         return;
1095                 }
1096                 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1097                 base = PAGE_ALIGN(base);
1098         }
1099         size &= PAGE_MASK;
1100
1101         if (base > MAX_MEMBLOCK_ADDR) {
1102                 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1103                                 base, base + size);
1104                 return;
1105         }
1106
1107         if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1108                 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1109                                 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1110                 size = MAX_MEMBLOCK_ADDR - base + 1;
1111         }
1112
1113         if (base + size < phys_offset) {
1114                 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1115                            base, base + size);
1116                 return;
1117         }
1118         if (base < phys_offset) {
1119                 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1120                            base, phys_offset);
1121                 size -= phys_offset - base;
1122                 base = phys_offset;
1123         }
1124         memblock_add(base, size);
1125 }
1126
1127 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1128                                         phys_addr_t size, bool nomap)
1129 {
1130         if (nomap)
1131                 return memblock_remove(base, size);
1132         return memblock_reserve(base, size);
1133 }
1134
1135 /*
1136  * called from unflatten_device_tree() to bootstrap devicetree itself
1137  * Architectures can override this definition if memblock isn't used
1138  */
1139 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
1140 {
1141         return __va(memblock_alloc(size, align));
1142 }
1143 #else
1144 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1145 {
1146         WARN_ON(1);
1147 }
1148
1149 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1150                                         phys_addr_t size, bool nomap)
1151 {
1152         pr_err("Reserved memory not supported, ignoring range %pa - %pa%s\n",
1153                   &base, &size, nomap ? " (nomap)" : "");
1154         return -ENOSYS;
1155 }
1156
1157 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
1158 {
1159         WARN_ON(1);
1160         return NULL;
1161 }
1162 #endif
1163
1164 bool __init early_init_dt_verify(void *params)
1165 {
1166         if (!params)
1167                 return false;
1168
1169         /* check device tree validity */
1170         if (fdt_check_header(params))
1171                 return false;
1172
1173         /* Setup flat device-tree pointer */
1174         initial_boot_params = params;
1175         of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1176                                 fdt_totalsize(initial_boot_params));
1177         return true;
1178 }
1179
1180
1181 void __init early_init_dt_scan_nodes(void)
1182 {
1183         /* Retrieve various information from the /chosen node */
1184         of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1185
1186         /* Initialize {size,address}-cells info */
1187         of_scan_flat_dt(early_init_dt_scan_root, NULL);
1188
1189         /* Setup memory, calling early_init_dt_add_memory_arch */
1190         of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1191 }
1192
1193 bool __init early_init_dt_scan(void *params)
1194 {
1195         bool status;
1196
1197         status = early_init_dt_verify(params);
1198         if (!status)
1199                 return false;
1200
1201         early_init_dt_scan_nodes();
1202         return true;
1203 }
1204
1205 /**
1206  * unflatten_device_tree - create tree of device_nodes from flat blob
1207  *
1208  * unflattens the device-tree passed by the firmware, creating the
1209  * tree of struct device_node. It also fills the "name" and "type"
1210  * pointers of the nodes so the normal device-tree walking functions
1211  * can be used.
1212  */
1213 void __init unflatten_device_tree(void)
1214 {
1215         __unflatten_device_tree(initial_boot_params, NULL, &of_root,
1216                                 early_init_dt_alloc_memory_arch);
1217
1218         /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1219         of_alias_scan(early_init_dt_alloc_memory_arch);
1220 }
1221
1222 /**
1223  * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1224  *
1225  * Copies and unflattens the device-tree passed by the firmware, creating the
1226  * tree of struct device_node. It also fills the "name" and "type"
1227  * pointers of the nodes so the normal device-tree walking functions
1228  * can be used. This should only be used when the FDT memory has not been
1229  * reserved such is the case when the FDT is built-in to the kernel init
1230  * section. If the FDT memory is reserved already then unflatten_device_tree
1231  * should be used instead.
1232  */
1233 void __init unflatten_and_copy_device_tree(void)
1234 {
1235         int size;
1236         void *dt;
1237
1238         if (!initial_boot_params) {
1239                 pr_warn("No valid device tree found, continuing without\n");
1240                 return;
1241         }
1242
1243         size = fdt_totalsize(initial_boot_params);
1244         dt = early_init_dt_alloc_memory_arch(size,
1245                                              roundup_pow_of_two(FDT_V17_SIZE));
1246
1247         if (dt) {
1248                 memcpy(dt, initial_boot_params, size);
1249                 initial_boot_params = dt;
1250         }
1251         unflatten_device_tree();
1252 }
1253
1254 #ifdef CONFIG_SYSFS
1255 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1256                                struct bin_attribute *bin_attr,
1257                                char *buf, loff_t off, size_t count)
1258 {
1259         memcpy(buf, initial_boot_params + off, count);
1260         return count;
1261 }
1262
1263 static int __init of_fdt_raw_init(void)
1264 {
1265         static struct bin_attribute of_fdt_raw_attr =
1266                 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1267
1268         if (!initial_boot_params)
1269                 return 0;
1270
1271         if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1272                                      fdt_totalsize(initial_boot_params))) {
1273                 pr_warn("fdt: not creating '/sys/firmware/fdt': CRC check failed\n");
1274                 return 0;
1275         }
1276         of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1277         return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1278 }
1279 late_initcall(of_fdt_raw_init);
1280 #endif
1281
1282 #endif /* CONFIG_OF_EARLY_FLATTREE */