drivers/of/fdt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Functions for working with the Flattened Device Tree data format
   4  *
   5  * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
   6  * benh@kernel.crashing.org
   7  */
   8
   9 #define pr_fmt(fmt)     "OF: fdt: " fmt
  10
  11 #include <linux/crc32.h>
  12 #include <linux/kernel.h>
  13 #include <linux/initrd.h>
  14 #include <linux/bootmem.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 #include "of_private.h"
  33
  34 /*
  35  * of_fdt_limit_memory - limit the number of regions in the /memory node
  36  * @limit: maximum entries
  37  *
  38  * Adjust the flattened device tree to have at most 'limit' number of
  39  * memory entries in the /memory node. This function may be called
  40  * any time after initial_boot_param is set.
  41  */
  42 void of_fdt_limit_memory(int limit)
  43 {
  44         int memory;
  45         int len;
  46         const void *val;
  47         int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
  48         int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
  49         const __be32 *addr_prop;
  50         const __be32 *size_prop;
  51         int root_offset;
  52         int cell_size;
  53
  54         root_offset = fdt_path_offset(initial_boot_params, "/");
  55         if (root_offset < 0)
  56                 return;
  57
  58         addr_prop = fdt_getprop(initial_boot_params, root_offset,
  59                                 "#address-cells", NULL);
  60         if (addr_prop)
  61                 nr_address_cells = fdt32_to_cpu(*addr_prop);
  62
  63         size_prop = fdt_getprop(initial_boot_params, root_offset,
  64                                 "#size-cells", NULL);
  65         if (size_prop)
  66                 nr_size_cells = fdt32_to_cpu(*size_prop);
  67
  68         cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
  69
  70         memory = fdt_path_offset(initial_boot_params, "/memory");
  71         if (memory > 0) {
  72                 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
  73                 if (len > limit*cell_size) {
  74                         len = limit*cell_size;
  75                         pr_debug("Limiting number of entries to %d\n", limit);
  76                         fdt_setprop(initial_boot_params, memory, "reg", val,
  77                                         len);
  78                 }
  79         }
  80 }
  81
  82 /**
  83  * of_fdt_is_compatible - Return true if given node from the given blob has
  84  * compat in its compatible list
  85  * @blob: A device tree blob
  86  * @node: node to test
  87  * @compat: compatible string to compare with compatible list.
  88  *
  89  * On match, returns a non-zero value with smaller values returned for more
  90  * specific compatible values.
  91  */
  92 static int of_fdt_is_compatible(const void *blob,
  93                       unsigned long node, const char *compat)
  94 {
  95         const char *cp;
  96         int cplen;
  97         unsigned long l, score = 0;
  98
  99         cp = fdt_getprop(blob, node, "compatible", &cplen);
 100         if (cp == NULL)
 101                 return 0;
 102         while (cplen > 0) {
 103                 score++;
 104                 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 105                         return score;
 106                 l = strlen(cp) + 1;
 107                 cp += l;
 108                 cplen -= l;
 109         }
 110
 111         return 0;
 112 }
 113
 114 /**
 115  * of_fdt_is_big_endian - Return true if given node needs BE MMIO accesses
 116  * @blob: A device tree blob
 117  * @node: node to test
 118  *
 119  * Returns true if the node has a "big-endian" property, or if the kernel
 120  * was compiled for BE *and* the node has a "native-endian" property.
 121  * Returns false otherwise.
 122  */
 123 bool of_fdt_is_big_endian(const void *blob, unsigned long node)
 124 {
 125         if (fdt_getprop(blob, node, "big-endian", NULL))
 126                 return true;
 127         if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
 128             fdt_getprop(blob, node, "native-endian", NULL))
 129                 return true;
 130         return false;
 131 }
 132
 133 static bool of_fdt_device_is_available(const void *blob, unsigned long node)
 134 {
 135         const char *status = fdt_getprop(blob, node, "status", NULL);
 136
 137         if (!status)
 138                 return true;
 139
 140         if (!strcmp(status, "ok") || !strcmp(status, "okay"))
 141                 return true;
 142
 143         return false;
 144 }
 145
 146 /**
 147  * of_fdt_match - Return true if node matches a list of compatible values
 148  */
 149 int of_fdt_match(const void *blob, unsigned long node,
 150                  const char *const *compat)
 151 {
 152         unsigned int tmp, score = 0;
 153
 154         if (!compat)
 155                 return 0;
 156
 157         while (*compat) {
 158                 tmp = of_fdt_is_compatible(blob, node, *compat);
 159                 if (tmp && (score == 0 || (tmp < score)))
 160                         score = tmp;
 161                 compat++;
 162         }
 163
 164         return score;
 165 }
 166
 167 static void *unflatten_dt_alloc(void **mem, unsigned long size,
 168                                        unsigned long align)
 169 {
 170         void *res;
 171
 172         *mem = PTR_ALIGN(*mem, align);
 173         res = *mem;
 174         *mem += size;
 175
 176         return res;
 177 }
 178
 179 static void populate_properties(const void *blob,
 180                                 int offset,
 181                                 void **mem,
 182                                 struct device_node *np,
 183                                 const char *nodename,
 184                                 bool dryrun)
 185 {
 186         struct property *pp, **pprev = NULL;
 187         int cur;
 188         bool has_name = false;
 189
 190         pprev = &np->properties;
 191         for (cur = fdt_first_property_offset(blob, offset);
 192              cur >= 0;
 193              cur = fdt_next_property_offset(blob, cur)) {
 194                 const __be32 *val;
 195                 const char *pname;
 196                 u32 sz;
 197
 198                 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
 199                 if (!val) {
 200                         pr_warn("Cannot locate property at 0x%x\n", cur);
 201                         continue;
 202                 }
 203
 204                 if (!pname) {
 205                         pr_warn("Cannot find property name at 0x%x\n", cur);
 206                         continue;
 207                 }
 208
 209                 if (!strcmp(pname, "name"))
 210                         has_name = true;
 211
 212                 pp = unflatten_dt_alloc(mem, sizeof(struct property),
 213                                         __alignof__(struct property));
 214                 if (dryrun)
 215                         continue;
 216
 217                 /* We accept flattened tree phandles either in
 218                  * ePAPR-style "phandle" properties, or the
 219                  * legacy "linux,phandle" properties.  If both
 220                  * appear and have different values, things
 221                  * will get weird. Don't do that.
 222                  */
 223                 if (!strcmp(pname, "phandle") ||
 224                     !strcmp(pname, "linux,phandle")) {
 225                         if (!np->phandle)
 226                                 np->phandle = be32_to_cpup(val);
 227                 }
 228
 229                 /* And we process the "ibm,phandle" property
 230                  * used in pSeries dynamic device tree
 231                  * stuff
 232                  */
 233                 if (!strcmp(pname, "ibm,phandle"))
 234                         np->phandle = be32_to_cpup(val);
 235
 236                 pp->name   = (char *)pname;
 237                 pp->length = sz;
 238                 pp->value  = (__be32 *)val;
 239                 *pprev     = pp;
 240                 pprev      = &pp->next;
 241         }
 242
 243         /* With version 0x10 we may not have the name property,
 244          * recreate it here from the unit name if absent
 245          */
 246         if (!has_name) {
 247                 const char *p = nodename, *ps = p, *pa = NULL;
 248                 int len;
 249
 250                 while (*p) {
 251                         if ((*p) == '@')
 252                                 pa = p;
 253                         else if ((*p) == '/')
 254                                 ps = p + 1;
 255                         p++;
 256                 }
 257
 258                 if (pa < ps)
 259                         pa = p;
 260                 len = (pa - ps) + 1;
 261                 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
 262                                         __alignof__(struct property));
 263                 if (!dryrun) {
 264                         pp->name   = "name";
 265                         pp->length = len;
 266                         pp->value  = pp + 1;
 267                         *pprev     = pp;
 268                         pprev      = &pp->next;
 269                         memcpy(pp->value, ps, len - 1);
 270                         ((char *)pp->value)[len - 1] = 0;
 271                         pr_debug("fixed up name for %s -> %s\n",
 272                                  nodename, (char *)pp->value);
 273                 }
 274         }
 275
 276         if (!dryrun)
 277                 *pprev = NULL;
 278 }
 279
 280 static bool populate_node(const void *blob,
 281                           int offset,
 282                           void **mem,
 283                           struct device_node *dad,
 284                           struct device_node **pnp,
 285                           bool dryrun)
 286 {
 287         struct device_node *np;
 288         const char *pathp;
 289         unsigned int l, allocl;
 290
 291         pathp = fdt_get_name(blob, offset, &l);
 292         if (!pathp) {
 293                 *pnp = NULL;
 294                 return false;
 295         }
 296
 297         allocl = ++l;
 298
 299         np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
 300                                 __alignof__(struct device_node));
 301         if (!dryrun) {
 302                 char *fn;
 303                 of_node_init(np);
 304                 np->full_name = fn = ((char *)np) + sizeof(*np);
 305
 306                 memcpy(fn, pathp, l);
 307
 308                 if (dad != NULL) {
 309                         np->parent = dad;
 310                         np->sibling = dad->child;
 311                         dad->child = np;
 312                 }
 313         }
 314
 315         populate_properties(blob, offset, mem, np, pathp, dryrun);
 316         if (!dryrun) {
 317                 np->name = of_get_property(np, "name", NULL);
 318                 np->type = of_get_property(np, "device_type", NULL);
 319
 320                 if (!np->name)
 321                         np->name = "<NULL>";
 322                 if (!np->type)
 323                         np->type = "<NULL>";
 324         }
 325
 326         *pnp = np;
 327         return true;
 328 }
 329
 330 static void reverse_nodes(struct device_node *parent)
 331 {
 332         struct device_node *child, *next;
 333
 334         /* In-depth first */
 335         child = parent->child;
 336         while (child) {
 337                 reverse_nodes(child);
 338
 339                 child = child->sibling;
 340         }
 341
 342         /* Reverse the nodes in the child list */
 343         child = parent->child;
 344         parent->child = NULL;
 345         while (child) {
 346                 next = child->sibling;
 347
 348                 child->sibling = parent->child;
 349                 parent->child = child;
 350                 child = next;
 351         }
 352 }
 353
 354 /**
 355  * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
 356  * @blob: The parent device tree blob
 357  * @mem: Memory chunk to use for allocating device nodes and properties
 358  * @dad: Parent struct device_node
 359  * @nodepp: The device_node tree created by the call
 360  *
 361  * It returns the size of unflattened device tree or error code
 362  */
 363 static int unflatten_dt_nodes(const void *blob,
 364                               void *mem,
 365                               struct device_node *dad,
 366                               struct device_node **nodepp)
 367 {
 368         struct device_node *root;
 369         int offset = 0, depth = 0, initial_depth = 0;
 370 #define FDT_MAX_DEPTH   64
 371         struct device_node *nps[FDT_MAX_DEPTH];
 372         void *base = mem;
 373         bool dryrun = !base;
 374
 375         if (nodepp)
 376                 *nodepp = NULL;
 377
 378         /*
 379          * We're unflattening device sub-tree if @dad is valid. There are
 380          * possibly multiple nodes in the first level of depth. We need
 381          * set @depth to 1 to make fdt_next_node() happy as it bails
 382          * immediately when negative @depth is found. Otherwise, the device
 383          * nodes except the first one won't be unflattened successfully.
 384          */
 385         if (dad)
 386                 depth = initial_depth = 1;
 387
 388         root = dad;
 389         nps[depth] = dad;
 390
 391         for (offset = 0;
 392              offset >= 0 && depth >= initial_depth;
 393              offset = fdt_next_node(blob, offset, &depth)) {
 394                 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
 395                         continue;
 396
 397                 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
 398                     !of_fdt_device_is_available(blob, offset))
 399                         continue;
 400
 401                 if (!populate_node(blob, offset, &mem, nps[depth],
 402                                    &nps[depth+1], dryrun))
 403                         return mem - base;
 404
 405                 if (!dryrun && nodepp && !*nodepp)
 406                         *nodepp = nps[depth+1];
 407                 if (!dryrun && !root)
 408                         root = nps[depth+1];
 409         }
 410
 411         if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 412                 pr_err("Error %d processing FDT\n", offset);
 413                 return -EINVAL;
 414         }
 415
 416         /*
 417          * Reverse the child list. Some drivers assumes node order matches .dts
 418          * node order
 419          */
 420         if (!dryrun)
 421                 reverse_nodes(root);
 422
 423         return mem - base;
 424 }
 425
 426 /**
 427  * __unflatten_device_tree - create tree of device_nodes from flat blob
 428  *
 429  * unflattens a device-tree, creating the
 430  * tree of struct device_node. It also fills the "name" and "type"
 431  * pointers of the nodes so the normal device-tree walking functions
 432  * can be used.
 433  * @blob: The blob to expand
 434  * @dad: Parent device node
 435  * @mynodes: The device_node tree created by the call
 436  * @dt_alloc: An allocator that provides a virtual address to memory
 437  * for the resulting tree
 438  * @detached: if true set OF_DETACHED on @mynodes
 439  *
 440  * Returns NULL on failure or the memory chunk containing the unflattened
 441  * device tree on success.
 442  */
 443 void *__unflatten_device_tree(const void *blob,
 444                               struct device_node *dad,
 445                               struct device_node **mynodes,
 446                               void *(*dt_alloc)(u64 size, u64 align),
 447                               bool detached)
 448 {
 449         int size;
 450         void *mem;
 451
 452         pr_debug(" -> unflatten_device_tree()\n");
 453
 454         if (!blob) {
 455                 pr_debug("No device tree pointer\n");
 456                 return NULL;
 457         }
 458
 459         pr_debug("Unflattening device tree:\n");
 460         pr_debug("magic: %08x\n", fdt_magic(blob));
 461         pr_debug("size: %08x\n", fdt_totalsize(blob));
 462         pr_debug("version: %08x\n", fdt_version(blob));
 463
 464         if (fdt_check_header(blob)) {
 465                 pr_err("Invalid device tree blob header\n");
 466                 return NULL;
 467         }
 468
 469         /* First pass, scan for size */
 470         size = unflatten_dt_nodes(blob, NULL, dad, NULL);
 471         if (size < 0)
 472                 return NULL;
 473
 474         size = ALIGN(size, 4);
 475         pr_debug("  size is %d, allocating...\n", size);
 476
 477         /* Allocate memory for the expanded device tree */
 478         mem = dt_alloc(size + 4, __alignof__(struct device_node));
 479         if (!mem)
 480                 return NULL;
 481
 482         memset(mem, 0, size);
 483
 484         *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 485
 486         pr_debug("  unflattening %p...\n", mem);
 487
 488         /* Second pass, do actual unflattening */
 489         unflatten_dt_nodes(blob, mem, dad, mynodes);
 490         if (be32_to_cpup(mem + size) != 0xdeadbeef)
 491                 pr_warning("End of tree marker overwritten: %08x\n",
 492                            be32_to_cpup(mem + size));
 493
 494         if (detached && mynodes) {
 495                 of_node_set_flag(*mynodes, OF_DETACHED);
 496                 pr_debug("unflattened tree is detached\n");
 497         }
 498
 499         pr_debug(" <- unflatten_device_tree()\n");
 500         return mem;
 501 }
 502
 503 static void *kernel_tree_alloc(u64 size, u64 align)
 504 {
 505         return kzalloc(size, GFP_KERNEL);
 506 }
 507
 508 static DEFINE_MUTEX(of_fdt_unflatten_mutex);
 509
 510 /**
 511  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 512  * @blob: Flat device tree blob
 513  * @dad: Parent device node
 514  * @mynodes: The device tree created by the call
 515  *
 516  * unflattens the device-tree passed by the firmware, creating the
 517  * tree of struct device_node. It also fills the "name" and "type"
 518  * pointers of the nodes so the normal device-tree walking functions
 519  * can be used.
 520  *
 521  * Returns NULL on failure or the memory chunk containing the unflattened
 522  * device tree on success.
 523  */
 524 void *of_fdt_unflatten_tree(const unsigned long *blob,
 525                             struct device_node *dad,
 526                             struct device_node **mynodes)
 527 {
 528         void *mem;
 529
 530         mutex_lock(&of_fdt_unflatten_mutex);
 531         mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
 532                                       true);
 533         mutex_unlock(&of_fdt_unflatten_mutex);
 534
 535         return mem;
 536 }
 537 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 538
 539 /* Everything below here references initial_boot_params directly. */
 540 int __initdata dt_root_addr_cells;
 541 int __initdata dt_root_size_cells;
 542
 543 void *initial_boot_params;
 544
 545 #ifdef CONFIG_OF_EARLY_FLATTREE
 546
 547 static u32 of_fdt_crc32;
 548
 549 /**
 550  * res_mem_reserve_reg() - reserve all memory described in 'reg' property
 551  */
 552 static int __init __reserved_mem_reserve_reg(unsigned long node,
 553                                              const char *uname)
 554 {
 555         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 556         phys_addr_t base, size;
 557         int len;
 558         const __be32 *prop;
 559         int nomap, first = 1;
 560
 561         prop = of_get_flat_dt_prop(node, "reg", &len);
 562         if (!prop)
 563                 return -ENOENT;
 564
 565         if (len && len % t_len != 0) {
 566                 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 567                        uname);
 568                 return -EINVAL;
 569         }
 570
 571         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 572
 573         while (len >= t_len) {
 574                 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 575                 size = dt_mem_next_cell(dt_root_size_cells, &prop);
 576
 577                 if (size &&
 578                     early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 579                         pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 580                                 uname, &base, (unsigned long)size / SZ_1M);
 581                 else
 582                         pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 583                                 uname, &base, (unsigned long)size / SZ_1M);
 584
 585                 len -= t_len;
 586                 if (first) {
 587                         fdt_reserved_mem_save_node(node, uname, base, size);
 588                         first = 0;
 589                 }
 590         }
 591         return 0;
 592 }
 593
 594 /**
 595  * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 596  * in /reserved-memory matches the values supported by the current implementation,
 597  * also check if ranges property has been provided
 598  */
 599 static int __init __reserved_mem_check_root(unsigned long node)
 600 {
 601         const __be32 *prop;
 602
 603         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 604         if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 605                 return -EINVAL;
 606
 607         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 608         if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 609                 return -EINVAL;
 610
 611         prop = of_get_flat_dt_prop(node, "ranges", NULL);
 612         if (!prop)
 613                 return -EINVAL;
 614         return 0;
 615 }
 616
 617 /**
 618  * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 619  */
 620 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 621                                           int depth, void *data)
 622 {
 623         static int found;
 624         int err;
 625
 626         if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 627                 if (__reserved_mem_check_root(node) != 0) {
 628                         pr_err("Reserved memory: unsupported node format, ignoring\n");
 629                         /* break scan */
 630                         return 1;
 631                 }
 632                 found = 1;
 633                 /* scan next node */
 634                 return 0;
 635         } else if (!found) {
 636                 /* scan next node */
 637                 return 0;
 638         } else if (found && depth < 2) {
 639                 /* scanning of /reserved-memory has been finished */
 640                 return 1;
 641         }
 642
 643         if (!of_fdt_device_is_available(initial_boot_params, node))
 644                 return 0;
 645
 646         err = __reserved_mem_reserve_reg(node, uname);
 647         if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 648                 fdt_reserved_mem_save_node(node, uname, 0, 0);
 649
 650         /* scan next node */
 651         return 0;
 652 }
 653
 654 /**
 655  * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 656  *
 657  * This function grabs memory from early allocator for device exclusive use
 658  * defined in device tree structures. It should be called by arch specific code
 659  * once the early allocator (i.e. memblock) has been fully activated.
 660  */
 661 void __init early_init_fdt_scan_reserved_mem(void)
 662 {
 663         int n;
 664         u64 base, size;
 665
 666         if (!initial_boot_params)
 667                 return;
 668
 669         /* Process header /memreserve/ fields */
 670         for (n = 0; ; n++) {
 671                 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 672                 if (!size)
 673                         break;
 674                 early_init_dt_reserve_memory_arch(base, size, 0);
 675         }
 676
 677         of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 678         fdt_init_reserved_mem();
 679 }
 680
 681 /**
 682  * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
 683  */
 684 void __init early_init_fdt_reserve_self(void)
 685 {
 686         if (!initial_boot_params)
 687                 return;
 688
 689         /* Reserve the dtb region */
 690         early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
 691                                           fdt_totalsize(initial_boot_params),
 692                                           0);
 693 }
 694
 695 /**
 696  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 697  * @it: callback function
 698  * @data: context data pointer
 699  *
 700  * This function is used to scan the flattened device-tree, it is
 701  * used to extract the memory information at boot before we can
 702  * unflatten the tree
 703  */
 704 int __init of_scan_flat_dt(int (*it)(unsigned long node,
 705                                      const char *uname, int depth,
 706                                      void *data),
 707                            void *data)
 708 {
 709         const void *blob = initial_boot_params;
 710         const char *pathp;
 711         int offset, rc = 0, depth = -1;
 712
 713         if (!blob)
 714                 return 0;
 715
 716         for (offset = fdt_next_node(blob, -1, &depth);
 717              offset >= 0 && depth >= 0 && !rc;
 718              offset = fdt_next_node(blob, offset, &depth)) {
 719
 720                 pathp = fdt_get_name(blob, offset, NULL);
 721                 if (*pathp == '/')
 722                         pathp = kbasename(pathp);
 723                 rc = it(offset, pathp, depth, data);
 724         }
 725         return rc;
 726 }
 727
 728 /**
 729  * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
 730  * @it: callback function
 731  * @data: context data pointer
 732  *
 733  * This function is used to scan sub-nodes of a node.
 734  */
 735 int __init of_scan_flat_dt_subnodes(unsigned long parent,
 736                                     int (*it)(unsigned long node,
 737                                               const char *uname,
 738                                               void *data),
 739                                     void *data)
 740 {
 741         const void *blob = initial_boot_params;
 742         int node;
 743
 744         fdt_for_each_subnode(node, blob, parent) {
 745                 const char *pathp;
 746                 int rc;
 747
 748                 pathp = fdt_get_name(blob, node, NULL);
 749                 if (*pathp == '/')
 750                         pathp = kbasename(pathp);
 751                 rc = it(node, pathp, data);
 752                 if (rc)
 753                         return rc;
 754         }
 755         return 0;
 756 }
 757
 758 /**
 759  * of_get_flat_dt_subnode_by_name - get the subnode by given name
 760  *
 761  * @node: the parent node
 762  * @uname: the name of subnode
 763  * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
 764  */
 765
 766 int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
 767 {
 768         return fdt_subnode_offset(initial_boot_params, node, uname);
 769 }
 770
 771 /**
 772  * of_get_flat_dt_root - find the root node in the flat blob
 773  */
 774 unsigned long __init of_get_flat_dt_root(void)
 775 {
 776         return 0;
 777 }
 778
 779 /**
 780  * of_get_flat_dt_size - Return the total size of the FDT
 781  */
 782 int __init of_get_flat_dt_size(void)
 783 {
 784         return fdt_totalsize(initial_boot_params);
 785 }
 786
 787 /**
 788  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 789  *
 790  * This function can be used within scan_flattened_dt callback to get
 791  * access to properties
 792  */
 793 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 794                                        int *size)
 795 {
 796         return fdt_getprop(initial_boot_params, node, name, size);
 797 }
 798
 799 /**
 800  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 801  * @node: node to test
 802  * @compat: compatible string to compare with compatible list.
 803  */
 804 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 805 {
 806         return of_fdt_is_compatible(initial_boot_params, node, compat);
 807 }
 808
 809 /**
 810  * of_flat_dt_match - Return true if node matches a list of compatible values
 811  */
 812 int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 813 {
 814         return of_fdt_match(initial_boot_params, node, compat);
 815 }
 816
 817 /**
 818  * of_get_flat_dt_prop - Given a node in the flat blob, return the phandle
 819  */
 820 uint32_t __init of_get_flat_dt_phandle(unsigned long node)
 821 {
 822         return fdt_get_phandle(initial_boot_params, node);
 823 }
 824
 825 struct fdt_scan_status {
 826         const char *name;
 827         int namelen;
 828         int depth;
 829         int found;
 830         int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 831         void *data;
 832 };
 833
 834 const char * __init of_flat_dt_get_machine_name(void)
 835 {
 836         const char *name;
 837         unsigned long dt_root = of_get_flat_dt_root();
 838
 839         name = of_get_flat_dt_prop(dt_root, "model", NULL);
 840         if (!name)
 841                 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 842         return name;
 843 }
 844
 845 /**
 846  * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 847  *
 848  * @default_match: A machine specific ptr to return in case of no match.
 849  * @get_next_compat: callback function to return next compatible match table.
 850  *
 851  * Iterate through machine match tables to find the best match for the machine
 852  * compatible string in the FDT.
 853  */
 854 const void * __init of_flat_dt_match_machine(const void *default_match,
 855                 const void * (*get_next_compat)(const char * const**))
 856 {
 857         const void *data = NULL;
 858         const void *best_data = default_match;
 859         const char *const *compat;
 860         unsigned long dt_root;
 861         unsigned int best_score = ~1, score = 0;
 862
 863         dt_root = of_get_flat_dt_root();
 864         while ((data = get_next_compat(&compat))) {
 865                 score = of_flat_dt_match(dt_root, compat);
 866                 if (score > 0 && score < best_score) {
 867                         best_data = data;
 868                         best_score = score;
 869                 }
 870         }
 871         if (!best_data) {
 872                 const char *prop;
 873                 int size;
 874
 875                 pr_err("\n unrecognized device tree list:\n[ ");
 876
 877                 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 878                 if (prop) {
 879                         while (size > 0) {
 880                                 printk("'%s' ", prop);
 881                                 size -= strlen(prop) + 1;
 882                                 prop += strlen(prop) + 1;
 883                         }
 884                 }
 885                 printk("]\n\n");
 886                 return NULL;
 887         }
 888
 889         pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 890
 891         return best_data;
 892 }
 893
 894 #ifdef CONFIG_BLK_DEV_INITRD
 895 #ifndef __early_init_dt_declare_initrd
 896 static void __early_init_dt_declare_initrd(unsigned long start,
 897                                            unsigned long end)
 898 {
 899         initrd_start = (unsigned long)__va(start);
 900         initrd_end = (unsigned long)__va(end);
 901         initrd_below_start_ok = 1;
 902 }
 903 #endif
 904
 905 /**
 906  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 907  * @node: reference to node containing initrd location ('chosen')
 908  */
 909 static void __init early_init_dt_check_for_initrd(unsigned long node)
 910 {
 911         u64 start, end;
 912         int len;
 913         const __be32 *prop;
 914
 915         pr_debug("Looking for initrd properties... ");
 916
 917         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 918         if (!prop)
 919                 return;
 920         start = of_read_number(prop, len/4);
 921
 922         prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 923         if (!prop)
 924                 return;
 925         end = of_read_number(prop, len/4);
 926
 927         __early_init_dt_declare_initrd(start, end);
 928
 929         pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 930                  (unsigned long long)start, (unsigned long long)end);
 931 }
 932 #else
 933 static inline void early_init_dt_check_for_initrd(unsigned long node)
 934 {
 935 }
 936 #endif /* CONFIG_BLK_DEV_INITRD */
 937
 938 #ifdef CONFIG_SERIAL_EARLYCON
 939
 940 int __init early_init_dt_scan_chosen_stdout(void)
 941 {
 942         int offset;
 943         const char *p, *q, *options = NULL;
 944         int l;
 945         const struct earlycon_id *match;
 946         const void *fdt = initial_boot_params;
 947
 948         offset = fdt_path_offset(fdt, "/chosen");
 949         if (offset < 0)
 950                 offset = fdt_path_offset(fdt, "/chosen@0");
 951         if (offset < 0)
 952                 return -ENOENT;
 953
 954         p = fdt_getprop(fdt, offset, "stdout-path", &l);
 955         if (!p)
 956                 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 957         if (!p || !l)
 958                 return -ENOENT;
 959
 960         q = strchrnul(p, ':');
 961         if (*q != '\0')
 962                 options = q + 1;
 963         l = q - p;
 964
 965         /* Get the node specified by stdout-path */
 966         offset = fdt_path_offset_namelen(fdt, p, l);
 967         if (offset < 0) {
 968                 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
 969                 return 0;
 970         }
 971
 972         for (match = __earlycon_table; match < __earlycon_table_end; match++) {
 973                 if (!match->compatible[0])
 974                         continue;
 975
 976                 if (fdt_node_check_compatible(fdt, offset, match->compatible))
 977                         continue;
 978
 979                 of_setup_earlycon(match, offset, options);
 980                 return 0;
 981         }
 982         return -ENODEV;
 983 }
 984 #endif
 985
 986 /**
 987  * early_init_dt_scan_root - fetch the top level address and size cells
 988  */
 989 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 990                                    int depth, void *data)
 991 {
 992         const __be32 *prop;
 993
 994         if (depth != 0)
 995                 return 0;
 996
 997         dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 998         dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 999
1000         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
1001         if (prop)
1002                 dt_root_size_cells = be32_to_cpup(prop);
1003         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
1004
1005         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
1006         if (prop)
1007                 dt_root_addr_cells = be32_to_cpup(prop);
1008         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
1009
1010         /* break now */
1011         return 1;
1012 }
1013
1014 u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
1015 {
1016         const __be32 *p = *cellp;
1017
1018         *cellp = p + s;
1019         return of_read_number(p, s);
1020 }
1021
1022 /**
1023  * early_init_dt_scan_memory - Look for and parse memory nodes
1024  */
1025 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
1026                                      int depth, void *data)
1027 {
1028         const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
1029         const __be32 *reg, *endp;
1030         int l;
1031         bool hotpluggable;
1032
1033         /* We are scanning "memory" nodes only */
1034         if (type == NULL) {
1035                 /*
1036                  * The longtrail doesn't have a device_type on the
1037                  * /memory node, so look for the node called /memory@0.
1038                  */
1039                 if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0)
1040                         return 0;
1041         } else if (strcmp(type, "memory") != 0)
1042                 return 0;
1043
1044         reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1045         if (reg == NULL)
1046                 reg = of_get_flat_dt_prop(node, "reg", &l);
1047         if (reg == NULL)
1048                 return 0;
1049
1050         endp = reg + (l / sizeof(__be32));
1051         hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1052
1053         pr_debug("memory scan node %s, reg size %d,\n", uname, l);
1054
1055         while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1056                 u64 base, size;
1057
1058                 base = dt_mem_next_cell(dt_root_addr_cells, &reg);
1059                 size = dt_mem_next_cell(dt_root_size_cells, &reg);
1060
1061                 if (size == 0)
1062                         continue;
1063                 pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
1064                     (unsigned long long)size);
1065
1066                 early_init_dt_add_memory_arch(base, size);
1067
1068                 if (!hotpluggable)
1069                         continue;
1070
1071                 if (early_init_dt_mark_hotplug_memory_arch(base, size))
1072                         pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1073                                 base, base + size);
1074         }
1075
1076         return 0;
1077 }
1078
1079 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
1080                                      int depth, void *data)
1081 {
1082         int l;
1083         const char *p;
1084
1085         pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
1086
1087         if (depth != 1 || !data ||
1088             (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
1089                 return 0;
1090
1091         early_init_dt_check_for_initrd(node);
1092
1093         /* Retrieve command line */
1094         p = of_get_flat_dt_prop(node, "bootargs", &l);
1095         if (p != NULL && l > 0)
1096                 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
1097
1098         /*
1099          * CONFIG_CMDLINE is meant to be a default in case nothing else
1100          * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1101          * is set in which case we override whatever was found earlier.
1102          */
1103 #ifdef CONFIG_CMDLINE
1104 #if defined(CONFIG_CMDLINE_EXTEND)
1105         strlcat(data, " ", COMMAND_LINE_SIZE);
1106         strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1107 #elif defined(CONFIG_CMDLINE_FORCE)
1108         strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1109 #else
1110         /* No arguments from boot loader, use kernel's  cmdl*/
1111         if (!((char *)data)[0])
1112                 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1113 #endif
1114 #endif /* CONFIG_CMDLINE */
1115
1116         pr_debug("Command line is: %s\n", (char*)data);
1117
1118         /* break now */
1119         return 1;
1120 }
1121
1122 #ifdef CONFIG_HAVE_MEMBLOCK
1123 #ifndef MIN_MEMBLOCK_ADDR
1124 #define MIN_MEMBLOCK_ADDR       __pa(PAGE_OFFSET)
1125 #endif
1126 #ifndef MAX_MEMBLOCK_ADDR
1127 #define MAX_MEMBLOCK_ADDR       ((phys_addr_t)~0)
1128 #endif
1129
1130 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1131 {
1132         const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1133
1134         if (!PAGE_ALIGNED(base)) {
1135                 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1136                         pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1137                                 base, base + size);
1138                         return;
1139                 }
1140                 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1141                 base = PAGE_ALIGN(base);
1142         }
1143         size &= PAGE_MASK;
1144
1145         if (base > MAX_MEMBLOCK_ADDR) {
1146                 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1147                                 base, base + size);
1148                 return;
1149         }
1150
1151         if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1152                 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1153                                 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1154                 size = MAX_MEMBLOCK_ADDR - base + 1;
1155         }
1156
1157         if (base + size < phys_offset) {
1158                 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1159                            base, base + size);
1160                 return;
1161         }
1162         if (base < phys_offset) {
1163                 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1164                            base, phys_offset);
1165                 size -= phys_offset - base;
1166                 base = phys_offset;
1167         }
1168         memblock_add(base, size);
1169 }
1170
1171 int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1172 {
1173         return memblock_mark_hotplug(base, size);
1174 }
1175
1176 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1177                                         phys_addr_t size, bool nomap)
1178 {
1179         if (nomap)
1180                 return memblock_remove(base, size);
1181         return memblock_reserve(base, size);
1182 }
1183
1184 #else
1185 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1186 {
1187         WARN_ON(1);
1188 }
1189
1190 int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1191 {
1192         return -ENOSYS;
1193 }
1194
1195 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1196                                         phys_addr_t size, bool nomap)
1197 {
1198         pr_err("Reserved memory not supported, ignoring range %pa - %pa%s\n",
1199                   &base, &size, nomap ? " (nomap)" : "");
1200         return -ENOSYS;
1201 }
1202 #endif
1203
1204 static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1205 {
1206         return memblock_virt_alloc(size, align);
1207 }
1208
1209 bool __init early_init_dt_verify(void *params)
1210 {
1211         if (!params)
1212                 return false;
1213
1214         /* check device tree validity */
1215         if (fdt_check_header(params))
1216                 return false;
1217
1218         /* Setup flat device-tree pointer */
1219         initial_boot_params = params;
1220         of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1221                                 fdt_totalsize(initial_boot_params));
1222         return true;
1223 }
1224
1225
1226 void __init early_init_dt_scan_nodes(void)
1227 {
1228         /* Retrieve various information from the /chosen node */
1229         of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1230
1231         /* Initialize {size,address}-cells info */
1232         of_scan_flat_dt(early_init_dt_scan_root, NULL);
1233
1234         /* Setup memory, calling early_init_dt_add_memory_arch */
1235         of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1236 }
1237
1238 bool __init early_init_dt_scan(void *params)
1239 {
1240         bool status;
1241
1242         status = early_init_dt_verify(params);
1243         if (!status)
1244                 return false;
1245
1246         early_init_dt_scan_nodes();
1247         return true;
1248 }
1249
1250 /**
1251  * unflatten_device_tree - create tree of device_nodes from flat blob
1252  *
1253  * unflattens the device-tree passed by the firmware, creating the
1254  * tree of struct device_node. It also fills the "name" and "type"
1255  * pointers of the nodes so the normal device-tree walking functions
1256  * can be used.
1257  */
1258 void __init unflatten_device_tree(void)
1259 {
1260         __unflatten_device_tree(initial_boot_params, NULL, &of_root,
1261                                 early_init_dt_alloc_memory_arch, false);
1262
1263         /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1264         of_alias_scan(early_init_dt_alloc_memory_arch);
1265
1266         unittest_unflatten_overlay_base();
1267 }
1268
1269 /**
1270  * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1271  *
1272  * Copies and unflattens the device-tree passed by the firmware, creating the
1273  * tree of struct device_node. It also fills the "name" and "type"
1274  * pointers of the nodes so the normal device-tree walking functions
1275  * can be used. This should only be used when the FDT memory has not been
1276  * reserved such is the case when the FDT is built-in to the kernel init
1277  * section. If the FDT memory is reserved already then unflatten_device_tree
1278  * should be used instead.
1279  */
1280 void __init unflatten_and_copy_device_tree(void)
1281 {
1282         int size;
1283         void *dt;
1284
1285         if (!initial_boot_params) {
1286                 pr_warn("No valid device tree found, continuing without\n");
1287                 return;
1288         }
1289
1290         size = fdt_totalsize(initial_boot_params);
1291         dt = early_init_dt_alloc_memory_arch(size,
1292                                              roundup_pow_of_two(FDT_V17_SIZE));
1293
1294         if (dt) {
1295                 memcpy(dt, initial_boot_params, size);
1296                 initial_boot_params = dt;
1297         }
1298         unflatten_device_tree();
1299 }
1300
1301 #ifdef CONFIG_SYSFS
1302 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1303                                struct bin_attribute *bin_attr,
1304                                char *buf, loff_t off, size_t count)
1305 {
1306         memcpy(buf, initial_boot_params + off, count);
1307         return count;
1308 }
1309
1310 static int __init of_fdt_raw_init(void)
1311 {
1312         static struct bin_attribute of_fdt_raw_attr =
1313                 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1314
1315         if (!initial_boot_params)
1316                 return 0;
1317
1318         if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1319                                      fdt_totalsize(initial_boot_params))) {
1320                 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1321                 return 0;
1322         }
1323         of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1324         return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1325 }
1326 late_initcall(of_fdt_raw_init);
1327 #endif
1328
1329 #endif /* CONFIG_OF_EARLY_FLATTREE */