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/memblock.h>
  15 #include <linux/mutex.h>
  16 #include <linux/of.h>
  17 #include <linux/of_fdt.h>
  18 #include <linux/of_reserved_mem.h>
  19 #include <linux/sizes.h>
  20 #include <linux/string.h>
  21 #include <linux/errno.h>
  22 #include <linux/slab.h>
  23 #include <linux/libfdt.h>
  24 #include <linux/debugfs.h>
  25 #include <linux/serial_core.h>
  26 #include <linux/sysfs.h>
  27 #include <linux/random.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 __init 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 static bool of_fdt_device_is_available(const void *blob, unsigned long node)
  83 {
  84         const char *status = fdt_getprop(blob, node, "status", NULL);
  85
  86         if (!status)
  87                 return true;
  88
  89         if (!strcmp(status, "ok") || !strcmp(status, "okay"))
  90                 return true;
  91
  92         return false;
  93 }
  94
  95 static void *unflatten_dt_alloc(void **mem, unsigned long size,
  96                                        unsigned long align)
  97 {
  98         void *res;
  99
 100         *mem = PTR_ALIGN(*mem, align);
 101         res = *mem;
 102         *mem += size;
 103
 104         return res;
 105 }
 106
 107 static void populate_properties(const void *blob,
 108                                 int offset,
 109                                 void **mem,
 110                                 struct device_node *np,
 111                                 const char *nodename,
 112                                 bool dryrun)
 113 {
 114         struct property *pp, **pprev = NULL;
 115         int cur;
 116         bool has_name = false;
 117
 118         pprev = &np->properties;
 119         for (cur = fdt_first_property_offset(blob, offset);
 120              cur >= 0;
 121              cur = fdt_next_property_offset(blob, cur)) {
 122                 const __be32 *val;
 123                 const char *pname;
 124                 u32 sz;
 125
 126                 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
 127                 if (!val) {
 128                         pr_warn("Cannot locate property at 0x%x\n", cur);
 129                         continue;
 130                 }
 131
 132                 if (!pname) {
 133                         pr_warn("Cannot find property name at 0x%x\n", cur);
 134                         continue;
 135                 }
 136
 137                 if (!strcmp(pname, "name"))
 138                         has_name = true;
 139
 140                 pp = unflatten_dt_alloc(mem, sizeof(struct property),
 141                                         __alignof__(struct property));
 142                 if (dryrun)
 143                         continue;
 144
 145                 /* We accept flattened tree phandles either in
 146                  * ePAPR-style "phandle" properties, or the
 147                  * legacy "linux,phandle" properties.  If both
 148                  * appear and have different values, things
 149                  * will get weird. Don't do that.
 150                  */
 151                 if (!strcmp(pname, "phandle") ||
 152                     !strcmp(pname, "linux,phandle")) {
 153                         if (!np->phandle)
 154                                 np->phandle = be32_to_cpup(val);
 155                 }
 156
 157                 /* And we process the "ibm,phandle" property
 158                  * used in pSeries dynamic device tree
 159                  * stuff
 160                  */
 161                 if (!strcmp(pname, "ibm,phandle"))
 162                         np->phandle = be32_to_cpup(val);
 163
 164                 pp->name   = (char *)pname;
 165                 pp->length = sz;
 166                 pp->value  = (__be32 *)val;
 167                 *pprev     = pp;
 168                 pprev      = &pp->next;
 169         }
 170
 171         /* With version 0x10 we may not have the name property,
 172          * recreate it here from the unit name if absent
 173          */
 174         if (!has_name) {
 175                 const char *p = nodename, *ps = p, *pa = NULL;
 176                 int len;
 177
 178                 while (*p) {
 179                         if ((*p) == '@')
 180                                 pa = p;
 181                         else if ((*p) == '/')
 182                                 ps = p + 1;
 183                         p++;
 184                 }
 185
 186                 if (pa < ps)
 187                         pa = p;
 188                 len = (pa - ps) + 1;
 189                 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
 190                                         __alignof__(struct property));
 191                 if (!dryrun) {
 192                         pp->name   = "name";
 193                         pp->length = len;
 194                         pp->value  = pp + 1;
 195                         *pprev     = pp;
 196                         pprev      = &pp->next;
 197                         memcpy(pp->value, ps, len - 1);
 198                         ((char *)pp->value)[len - 1] = 0;
 199                         pr_debug("fixed up name for %s -> %s\n",
 200                                  nodename, (char *)pp->value);
 201                 }
 202         }
 203
 204         if (!dryrun)
 205                 *pprev = NULL;
 206 }
 207
 208 static bool populate_node(const void *blob,
 209                           int offset,
 210                           void **mem,
 211                           struct device_node *dad,
 212                           struct device_node **pnp,
 213                           bool dryrun)
 214 {
 215         struct device_node *np;
 216         const char *pathp;
 217         unsigned int l, allocl;
 218
 219         pathp = fdt_get_name(blob, offset, &l);
 220         if (!pathp) {
 221                 *pnp = NULL;
 222                 return false;
 223         }
 224
 225         allocl = ++l;
 226
 227         np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
 228                                 __alignof__(struct device_node));
 229         if (!dryrun) {
 230                 char *fn;
 231                 of_node_init(np);
 232                 np->full_name = fn = ((char *)np) + sizeof(*np);
 233
 234                 memcpy(fn, pathp, l);
 235
 236                 if (dad != NULL) {
 237                         np->parent = dad;
 238                         np->sibling = dad->child;
 239                         dad->child = np;
 240                 }
 241         }
 242
 243         populate_properties(blob, offset, mem, np, pathp, dryrun);
 244         if (!dryrun) {
 245                 np->name = of_get_property(np, "name", NULL);
 246                 if (!np->name)
 247                         np->name = "<NULL>";
 248         }
 249
 250         *pnp = np;
 251         return true;
 252 }
 253
 254 static void reverse_nodes(struct device_node *parent)
 255 {
 256         struct device_node *child, *next;
 257
 258         /* In-depth first */
 259         child = parent->child;
 260         while (child) {
 261                 reverse_nodes(child);
 262
 263                 child = child->sibling;
 264         }
 265
 266         /* Reverse the nodes in the child list */
 267         child = parent->child;
 268         parent->child = NULL;
 269         while (child) {
 270                 next = child->sibling;
 271
 272                 child->sibling = parent->child;
 273                 parent->child = child;
 274                 child = next;
 275         }
 276 }
 277
 278 /**
 279  * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
 280  * @blob: The parent device tree blob
 281  * @mem: Memory chunk to use for allocating device nodes and properties
 282  * @dad: Parent struct device_node
 283  * @nodepp: The device_node tree created by the call
 284  *
 285  * It returns the size of unflattened device tree or error code
 286  */
 287 static int unflatten_dt_nodes(const void *blob,
 288                               void *mem,
 289                               struct device_node *dad,
 290                               struct device_node **nodepp)
 291 {
 292         struct device_node *root;
 293         int offset = 0, depth = 0, initial_depth = 0;
 294 #define FDT_MAX_DEPTH   64
 295         struct device_node *nps[FDT_MAX_DEPTH];
 296         void *base = mem;
 297         bool dryrun = !base;
 298
 299         if (nodepp)
 300                 *nodepp = NULL;
 301
 302         /*
 303          * We're unflattening device sub-tree if @dad is valid. There are
 304          * possibly multiple nodes in the first level of depth. We need
 305          * set @depth to 1 to make fdt_next_node() happy as it bails
 306          * immediately when negative @depth is found. Otherwise, the device
 307          * nodes except the first one won't be unflattened successfully.
 308          */
 309         if (dad)
 310                 depth = initial_depth = 1;
 311
 312         root = dad;
 313         nps[depth] = dad;
 314
 315         for (offset = 0;
 316              offset >= 0 && depth >= initial_depth;
 317              offset = fdt_next_node(blob, offset, &depth)) {
 318                 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
 319                         continue;
 320
 321                 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
 322                     !of_fdt_device_is_available(blob, offset))
 323                         continue;
 324
 325                 if (!populate_node(blob, offset, &mem, nps[depth],
 326                                    &nps[depth+1], dryrun))
 327                         return mem - base;
 328
 329                 if (!dryrun && nodepp && !*nodepp)
 330                         *nodepp = nps[depth+1];
 331                 if (!dryrun && !root)
 332                         root = nps[depth+1];
 333         }
 334
 335         if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 336                 pr_err("Error %d processing FDT\n", offset);
 337                 return -EINVAL;
 338         }
 339
 340         /*
 341          * Reverse the child list. Some drivers assumes node order matches .dts
 342          * node order
 343          */
 344         if (!dryrun)
 345                 reverse_nodes(root);
 346
 347         return mem - base;
 348 }
 349
 350 /**
 351  * __unflatten_device_tree - create tree of device_nodes from flat blob
 352  *
 353  * unflattens a device-tree, creating the
 354  * tree of struct device_node. It also fills the "name" and "type"
 355  * pointers of the nodes so the normal device-tree walking functions
 356  * can be used.
 357  * @blob: The blob to expand
 358  * @dad: Parent device node
 359  * @mynodes: The device_node tree created by the call
 360  * @dt_alloc: An allocator that provides a virtual address to memory
 361  * for the resulting tree
 362  * @detached: if true set OF_DETACHED on @mynodes
 363  *
 364  * Returns NULL on failure or the memory chunk containing the unflattened
 365  * device tree on success.
 366  */
 367 void *__unflatten_device_tree(const void *blob,
 368                               struct device_node *dad,
 369                               struct device_node **mynodes,
 370                               void *(*dt_alloc)(u64 size, u64 align),
 371                               bool detached)
 372 {
 373         int size;
 374         void *mem;
 375
 376         pr_debug(" -> unflatten_device_tree()\n");
 377
 378         if (!blob) {
 379                 pr_debug("No device tree pointer\n");
 380                 return NULL;
 381         }
 382
 383         pr_debug("Unflattening device tree:\n");
 384         pr_debug("magic: %08x\n", fdt_magic(blob));
 385         pr_debug("size: %08x\n", fdt_totalsize(blob));
 386         pr_debug("version: %08x\n", fdt_version(blob));
 387
 388         if (fdt_check_header(blob)) {
 389                 pr_err("Invalid device tree blob header\n");
 390                 return NULL;
 391         }
 392
 393         /* First pass, scan for size */
 394         size = unflatten_dt_nodes(blob, NULL, dad, NULL);
 395         if (size < 0)
 396                 return NULL;
 397
 398         size = ALIGN(size, 4);
 399         pr_debug("  size is %d, allocating...\n", size);
 400
 401         /* Allocate memory for the expanded device tree */
 402         mem = dt_alloc(size + 4, __alignof__(struct device_node));
 403         if (!mem)
 404                 return NULL;
 405
 406         memset(mem, 0, size);
 407
 408         *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 409
 410         pr_debug("  unflattening %p...\n", mem);
 411
 412         /* Second pass, do actual unflattening */
 413         unflatten_dt_nodes(blob, mem, dad, mynodes);
 414         if (be32_to_cpup(mem + size) != 0xdeadbeef)
 415                 pr_warn("End of tree marker overwritten: %08x\n",
 416                         be32_to_cpup(mem + size));
 417
 418         if (detached && mynodes) {
 419                 of_node_set_flag(*mynodes, OF_DETACHED);
 420                 pr_debug("unflattened tree is detached\n");
 421         }
 422
 423         pr_debug(" <- unflatten_device_tree()\n");
 424         return mem;
 425 }
 426
 427 static void *kernel_tree_alloc(u64 size, u64 align)
 428 {
 429         return kzalloc(size, GFP_KERNEL);
 430 }
 431
 432 static DEFINE_MUTEX(of_fdt_unflatten_mutex);
 433
 434 /**
 435  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 436  * @blob: Flat device tree blob
 437  * @dad: Parent device node
 438  * @mynodes: The device tree created by the call
 439  *
 440  * unflattens the device-tree passed by the firmware, creating the
 441  * tree of struct device_node. It also fills the "name" and "type"
 442  * pointers of the nodes so the normal device-tree walking functions
 443  * can be used.
 444  *
 445  * Returns NULL on failure or the memory chunk containing the unflattened
 446  * device tree on success.
 447  */
 448 void *of_fdt_unflatten_tree(const unsigned long *blob,
 449                             struct device_node *dad,
 450                             struct device_node **mynodes)
 451 {
 452         void *mem;
 453
 454         mutex_lock(&of_fdt_unflatten_mutex);
 455         mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
 456                                       true);
 457         mutex_unlock(&of_fdt_unflatten_mutex);
 458
 459         return mem;
 460 }
 461 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 462
 463 /* Everything below here references initial_boot_params directly. */
 464 int __initdata dt_root_addr_cells;
 465 int __initdata dt_root_size_cells;
 466
 467 void *initial_boot_params __ro_after_init;
 468
 469 #ifdef CONFIG_OF_EARLY_FLATTREE
 470
 471 static u32 of_fdt_crc32;
 472
 473 /**
 474  * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
 475  */
 476 static int __init __reserved_mem_reserve_reg(unsigned long node,
 477                                              const char *uname)
 478 {
 479         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 480         phys_addr_t base, size;
 481         int len;
 482         const __be32 *prop;
 483         int first = 1;
 484         bool nomap;
 485
 486         prop = of_get_flat_dt_prop(node, "reg", &len);
 487         if (!prop)
 488                 return -ENOENT;
 489
 490         if (len && len % t_len != 0) {
 491                 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 492                        uname);
 493                 return -EINVAL;
 494         }
 495
 496         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 497
 498         while (len >= t_len) {
 499                 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 500                 size = dt_mem_next_cell(dt_root_size_cells, &prop);
 501
 502                 if (size &&
 503                     early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 504                         pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 505                                 uname, &base, (unsigned long)size / SZ_1M);
 506                 else
 507                         pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 508                                 uname, &base, (unsigned long)size / SZ_1M);
 509
 510                 len -= t_len;
 511                 if (first) {
 512                         fdt_reserved_mem_save_node(node, uname, base, size);
 513                         first = 0;
 514                 }
 515         }
 516         return 0;
 517 }
 518
 519 /**
 520  * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 521  * in /reserved-memory matches the values supported by the current implementation,
 522  * also check if ranges property has been provided
 523  */
 524 static int __init __reserved_mem_check_root(unsigned long node)
 525 {
 526         const __be32 *prop;
 527
 528         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 529         if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 530                 return -EINVAL;
 531
 532         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 533         if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 534                 return -EINVAL;
 535
 536         prop = of_get_flat_dt_prop(node, "ranges", NULL);
 537         if (!prop)
 538                 return -EINVAL;
 539         return 0;
 540 }
 541
 542 /**
 543  * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 544  */
 545 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 546                                           int depth, void *data)
 547 {
 548         static int found;
 549         int err;
 550
 551         if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 552                 if (__reserved_mem_check_root(node) != 0) {
 553                         pr_err("Reserved memory: unsupported node format, ignoring\n");
 554                         /* break scan */
 555                         return 1;
 556                 }
 557                 found = 1;
 558                 /* scan next node */
 559                 return 0;
 560         } else if (!found) {
 561                 /* scan next node */
 562                 return 0;
 563         } else if (found && depth < 2) {
 564                 /* scanning of /reserved-memory has been finished */
 565                 return 1;
 566         }
 567
 568         if (!of_fdt_device_is_available(initial_boot_params, node))
 569                 return 0;
 570
 571         err = __reserved_mem_reserve_reg(node, uname);
 572         if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 573                 fdt_reserved_mem_save_node(node, uname, 0, 0);
 574
 575         /* scan next node */
 576         return 0;
 577 }
 578
 579 /**
 580  * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 581  *
 582  * This function grabs memory from early allocator for device exclusive use
 583  * defined in device tree structures. It should be called by arch specific code
 584  * once the early allocator (i.e. memblock) has been fully activated.
 585  */
 586 void __init early_init_fdt_scan_reserved_mem(void)
 587 {
 588         int n;
 589         u64 base, size;
 590
 591         if (!initial_boot_params)
 592                 return;
 593
 594         /* Process header /memreserve/ fields */
 595         for (n = 0; ; n++) {
 596                 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 597                 if (!size)
 598                         break;
 599                 early_init_dt_reserve_memory_arch(base, size, false);
 600         }
 601
 602         of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 603         fdt_init_reserved_mem();
 604 }
 605
 606 /**
 607  * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
 608  */
 609 void __init early_init_fdt_reserve_self(void)
 610 {
 611         if (!initial_boot_params)
 612                 return;
 613
 614         /* Reserve the dtb region */
 615         early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
 616                                           fdt_totalsize(initial_boot_params),
 617                                           false);
 618 }
 619
 620 /**
 621  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 622  * @it: callback function
 623  * @data: context data pointer
 624  *
 625  * This function is used to scan the flattened device-tree, it is
 626  * used to extract the memory information at boot before we can
 627  * unflatten the tree
 628  */
 629 int __init of_scan_flat_dt(int (*it)(unsigned long node,
 630                                      const char *uname, int depth,
 631                                      void *data),
 632                            void *data)
 633 {
 634         const void *blob = initial_boot_params;
 635         const char *pathp;
 636         int offset, rc = 0, depth = -1;
 637
 638         if (!blob)
 639                 return 0;
 640
 641         for (offset = fdt_next_node(blob, -1, &depth);
 642              offset >= 0 && depth >= 0 && !rc;
 643              offset = fdt_next_node(blob, offset, &depth)) {
 644
 645                 pathp = fdt_get_name(blob, offset, NULL);
 646                 rc = it(offset, pathp, depth, data);
 647         }
 648         return rc;
 649 }
 650
 651 /**
 652  * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
 653  * @it: callback function
 654  * @data: context data pointer
 655  *
 656  * This function is used to scan sub-nodes of a node.
 657  */
 658 int __init of_scan_flat_dt_subnodes(unsigned long parent,
 659                                     int (*it)(unsigned long node,
 660                                               const char *uname,
 661                                               void *data),
 662                                     void *data)
 663 {
 664         const void *blob = initial_boot_params;
 665         int node;
 666
 667         fdt_for_each_subnode(node, blob, parent) {
 668                 const char *pathp;
 669                 int rc;
 670
 671                 pathp = fdt_get_name(blob, node, NULL);
 672                 rc = it(node, pathp, data);
 673                 if (rc)
 674                         return rc;
 675         }
 676         return 0;
 677 }
 678
 679 /**
 680  * of_get_flat_dt_subnode_by_name - get the subnode by given name
 681  *
 682  * @node: the parent node
 683  * @uname: the name of subnode
 684  * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
 685  */
 686
 687 int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
 688 {
 689         return fdt_subnode_offset(initial_boot_params, node, uname);
 690 }
 691
 692 /**
 693  * of_get_flat_dt_root - find the root node in the flat blob
 694  */
 695 unsigned long __init of_get_flat_dt_root(void)
 696 {
 697         return 0;
 698 }
 699
 700 /**
 701  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 702  *
 703  * This function can be used within scan_flattened_dt callback to get
 704  * access to properties
 705  */
 706 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 707                                        int *size)
 708 {
 709         return fdt_getprop(initial_boot_params, node, name, size);
 710 }
 711
 712 /**
 713  * of_fdt_is_compatible - Return true if given node from the given blob has
 714  * compat in its compatible list
 715  * @blob: A device tree blob
 716  * @node: node to test
 717  * @compat: compatible string to compare with compatible list.
 718  *
 719  * On match, returns a non-zero value with smaller values returned for more
 720  * specific compatible values.
 721  */
 722 static int of_fdt_is_compatible(const void *blob,
 723                       unsigned long node, const char *compat)
 724 {
 725         const char *cp;
 726         int cplen;
 727         unsigned long l, score = 0;
 728
 729         cp = fdt_getprop(blob, node, "compatible", &cplen);
 730         if (cp == NULL)
 731                 return 0;
 732         while (cplen > 0) {
 733                 score++;
 734                 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 735                         return score;
 736                 l = strlen(cp) + 1;
 737                 cp += l;
 738                 cplen -= l;
 739         }
 740
 741         return 0;
 742 }
 743
 744 /**
 745  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 746  * @node: node to test
 747  * @compat: compatible string to compare with compatible list.
 748  */
 749 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 750 {
 751         return of_fdt_is_compatible(initial_boot_params, node, compat);
 752 }
 753
 754 /**
 755  * of_flat_dt_match - Return true if node matches a list of compatible values
 756  */
 757 static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 758 {
 759         unsigned int tmp, score = 0;
 760
 761         if (!compat)
 762                 return 0;
 763
 764         while (*compat) {
 765                 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
 766                 if (tmp && (score == 0 || (tmp < score)))
 767                         score = tmp;
 768                 compat++;
 769         }
 770
 771         return score;
 772 }
 773
 774 /**
 775  * of_get_flat_dt_prop - Given a node in the flat blob, return the phandle
 776  */
 777 uint32_t __init of_get_flat_dt_phandle(unsigned long node)
 778 {
 779         return fdt_get_phandle(initial_boot_params, node);
 780 }
 781
 782 struct fdt_scan_status {
 783         const char *name;
 784         int namelen;
 785         int depth;
 786         int found;
 787         int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 788         void *data;
 789 };
 790
 791 const char * __init of_flat_dt_get_machine_name(void)
 792 {
 793         const char *name;
 794         unsigned long dt_root = of_get_flat_dt_root();
 795
 796         name = of_get_flat_dt_prop(dt_root, "model", NULL);
 797         if (!name)
 798                 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 799         return name;
 800 }
 801
 802 /**
 803  * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 804  *
 805  * @default_match: A machine specific ptr to return in case of no match.
 806  * @get_next_compat: callback function to return next compatible match table.
 807  *
 808  * Iterate through machine match tables to find the best match for the machine
 809  * compatible string in the FDT.
 810  */
 811 const void * __init of_flat_dt_match_machine(const void *default_match,
 812                 const void * (*get_next_compat)(const char * const**))
 813 {
 814         const void *data = NULL;
 815         const void *best_data = default_match;
 816         const char *const *compat;
 817         unsigned long dt_root;
 818         unsigned int best_score = ~1, score = 0;
 819
 820         dt_root = of_get_flat_dt_root();
 821         while ((data = get_next_compat(&compat))) {
 822                 score = of_flat_dt_match(dt_root, compat);
 823                 if (score > 0 && score < best_score) {
 824                         best_data = data;
 825                         best_score = score;
 826                 }
 827         }
 828         if (!best_data) {
 829                 const char *prop;
 830                 int size;
 831
 832                 pr_err("\n unrecognized device tree list:\n[ ");
 833
 834                 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 835                 if (prop) {
 836                         while (size > 0) {
 837                                 printk("'%s' ", prop);
 838                                 size -= strlen(prop) + 1;
 839                                 prop += strlen(prop) + 1;
 840                         }
 841                 }
 842                 printk("]\n\n");
 843                 return NULL;
 844         }
 845
 846         pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 847
 848         return best_data;
 849 }
 850
 851 #ifdef CONFIG_BLK_DEV_INITRD
 852 static void __early_init_dt_declare_initrd(unsigned long start,
 853                                            unsigned long end)
 854 {
 855         /* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is
 856          * enabled since __va() is called too early. ARM64 does make use
 857          * of phys_initrd_start/phys_initrd_size so we can skip this
 858          * conversion.
 859          */
 860         if (!IS_ENABLED(CONFIG_ARM64)) {
 861                 initrd_start = (unsigned long)__va(start);
 862                 initrd_end = (unsigned long)__va(end);
 863                 initrd_below_start_ok = 1;
 864         }
 865 }
 866
 867 /**
 868  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 869  * @node: reference to node containing initrd location ('chosen')
 870  */
 871 static void __init early_init_dt_check_for_initrd(unsigned long node)
 872 {
 873         u64 start, end;
 874         int len;
 875         const __be32 *prop;
 876
 877         pr_debug("Looking for initrd properties... ");
 878
 879         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 880         if (!prop)
 881                 return;
 882         start = of_read_number(prop, len/4);
 883
 884         prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 885         if (!prop)
 886                 return;
 887         end = of_read_number(prop, len/4);
 888
 889         __early_init_dt_declare_initrd(start, end);
 890         phys_initrd_start = start;
 891         phys_initrd_size = end - start;
 892
 893         pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 894                  (unsigned long long)start, (unsigned long long)end);
 895 }
 896 #else
 897 static inline void early_init_dt_check_for_initrd(unsigned long node)
 898 {
 899 }
 900 #endif /* CONFIG_BLK_DEV_INITRD */
 901
 902 #ifdef CONFIG_SERIAL_EARLYCON
 903
 904 int __init early_init_dt_scan_chosen_stdout(void)
 905 {
 906         int offset;
 907         const char *p, *q, *options = NULL;
 908         int l;
 909         const struct earlycon_id *match;
 910         const void *fdt = initial_boot_params;
 911
 912         offset = fdt_path_offset(fdt, "/chosen");
 913         if (offset < 0)
 914                 offset = fdt_path_offset(fdt, "/chosen@0");
 915         if (offset < 0)
 916                 return -ENOENT;
 917
 918         p = fdt_getprop(fdt, offset, "stdout-path", &l);
 919         if (!p)
 920                 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 921         if (!p || !l)
 922                 return -ENOENT;
 923
 924         q = strchrnul(p, ':');
 925         if (*q != '\0')
 926                 options = q + 1;
 927         l = q - p;
 928
 929         /* Get the node specified by stdout-path */
 930         offset = fdt_path_offset_namelen(fdt, p, l);
 931         if (offset < 0) {
 932                 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
 933                 return 0;
 934         }
 935
 936         for (match = __earlycon_table; match < __earlycon_table_end; match++) {
 937                 if (!match->compatible[0])
 938                         continue;
 939
 940                 if (fdt_node_check_compatible(fdt, offset, match->compatible))
 941                         continue;
 942
 943                 if (of_setup_earlycon(match, offset, options) == 0)
 944                         return 0;
 945         }
 946         return -ENODEV;
 947 }
 948 #endif
 949
 950 /**
 951  * early_init_dt_scan_root - fetch the top level address and size cells
 952  */
 953 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 954                                    int depth, void *data)
 955 {
 956         const __be32 *prop;
 957
 958         if (depth != 0)
 959                 return 0;
 960
 961         dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 962         dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 963
 964         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 965         if (prop)
 966                 dt_root_size_cells = be32_to_cpup(prop);
 967         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 968
 969         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 970         if (prop)
 971                 dt_root_addr_cells = be32_to_cpup(prop);
 972         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 973
 974         /* break now */
 975         return 1;
 976 }
 977
 978 u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
 979 {
 980         const __be32 *p = *cellp;
 981
 982         *cellp = p + s;
 983         return of_read_number(p, s);
 984 }
 985
 986 /**
 987  * early_init_dt_scan_memory - Look for and parse memory nodes
 988  */
 989 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 990                                      int depth, void *data)
 991 {
 992         const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 993         const __be32 *reg, *endp;
 994         int l;
 995         bool hotpluggable;
 996
 997         /* We are scanning "memory" nodes only */
 998         if (type == NULL || strcmp(type, "memory") != 0)
 999                 return 0;
1000
1001         reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1002         if (reg == NULL)
1003                 reg = of_get_flat_dt_prop(node, "reg", &l);
1004         if (reg == NULL)
1005                 return 0;
1006
1007         endp = reg + (l / sizeof(__be32));
1008         hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1009
1010         pr_debug("memory scan node %s, reg size %d,\n", uname, l);
1011
1012         while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1013                 u64 base, size;
1014
1015                 base = dt_mem_next_cell(dt_root_addr_cells, &reg);
1016                 size = dt_mem_next_cell(dt_root_size_cells, &reg);
1017
1018                 if (size == 0)
1019                         continue;
1020                 pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
1021                     (unsigned long long)size);
1022
1023                 early_init_dt_add_memory_arch(base, size);
1024
1025                 if (!hotpluggable)
1026                         continue;
1027
1028                 if (early_init_dt_mark_hotplug_memory_arch(base, size))
1029                         pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1030                                 base, base + size);
1031         }
1032
1033         return 0;
1034 }
1035
1036 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
1037                                      int depth, void *data)
1038 {
1039         int l;
1040         const char *p;
1041         const void *rng_seed;
1042
1043         pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
1044
1045         if (depth != 1 || !data ||
1046             (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
1047                 return 0;
1048
1049         early_init_dt_check_for_initrd(node);
1050
1051         /* Retrieve command line */
1052         p = of_get_flat_dt_prop(node, "bootargs", &l);
1053         if (p != NULL && l > 0)
1054                 strlcpy(data, p, min(l, COMMAND_LINE_SIZE));
1055
1056         /*
1057          * CONFIG_CMDLINE is meant to be a default in case nothing else
1058          * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1059          * is set in which case we override whatever was found earlier.
1060          */
1061 #ifdef CONFIG_CMDLINE
1062 #if defined(CONFIG_CMDLINE_EXTEND)
1063         strlcat(data, " ", COMMAND_LINE_SIZE);
1064         strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1065 #elif defined(CONFIG_CMDLINE_FORCE)
1066         strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1067 #else
1068         /* No arguments from boot loader, use kernel's  cmdl*/
1069         if (!((char *)data)[0])
1070                 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1071 #endif
1072 #endif /* CONFIG_CMDLINE */
1073
1074         pr_debug("Command line is: %s\n", (char *)data);
1075
1076         rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1077         if (rng_seed && l > 0) {
1078                 add_bootloader_randomness(rng_seed, l);
1079
1080                 /* try to clear seed so it won't be found. */
1081                 fdt_nop_property(initial_boot_params, node, "rng-seed");
1082
1083                 /* update CRC check value */
1084                 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1085                                 fdt_totalsize(initial_boot_params));
1086         }
1087
1088         /* break now */
1089         return 1;
1090 }
1091
1092 #ifndef MIN_MEMBLOCK_ADDR
1093 #define MIN_MEMBLOCK_ADDR       __pa(PAGE_OFFSET)
1094 #endif
1095 #ifndef MAX_MEMBLOCK_ADDR
1096 #define MAX_MEMBLOCK_ADDR       ((phys_addr_t)~0)
1097 #endif
1098
1099 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1100 {
1101         const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1102
1103         if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1104                 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1105                         base, base + size);
1106                 return;
1107         }
1108
1109         if (!PAGE_ALIGNED(base)) {
1110                 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1111                 base = PAGE_ALIGN(base);
1112         }
1113         size &= PAGE_MASK;
1114
1115         if (base > MAX_MEMBLOCK_ADDR) {
1116                 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1117                         base, base + size);
1118                 return;
1119         }
1120
1121         if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1122                 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1123                         ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1124                 size = MAX_MEMBLOCK_ADDR - base + 1;
1125         }
1126
1127         if (base + size < phys_offset) {
1128                 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1129                         base, base + size);
1130                 return;
1131         }
1132         if (base < phys_offset) {
1133                 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1134                         base, phys_offset);
1135                 size -= phys_offset - base;
1136                 base = phys_offset;
1137         }
1138         memblock_add(base, size);
1139 }
1140
1141 int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1142 {
1143         return memblock_mark_hotplug(base, size);
1144 }
1145
1146 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1147                                         phys_addr_t size, bool nomap)
1148 {
1149         if (nomap)
1150                 return memblock_remove(base, size);
1151         return memblock_reserve(base, size);
1152 }
1153
1154 static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1155 {
1156         void *ptr = memblock_alloc(size, align);
1157
1158         if (!ptr)
1159                 panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1160                       __func__, size, align);
1161
1162         return ptr;
1163 }
1164
1165 bool __init early_init_dt_verify(void *params)
1166 {
1167         if (!params)
1168                 return false;
1169
1170         /* check device tree validity */
1171         if (fdt_check_header(params))
1172                 return false;
1173
1174         /* Setup flat device-tree pointer */
1175         initial_boot_params = params;
1176         of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1177                                 fdt_totalsize(initial_boot_params));
1178         return true;
1179 }
1180
1181
1182 void __init early_init_dt_scan_nodes(void)
1183 {
1184         int rc = 0;
1185
1186         /* Retrieve various information from the /chosen node */
1187         rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1188         if (!rc)
1189                 pr_warn("No chosen node found, continuing without\n");
1190
1191         /* Initialize {size,address}-cells info */
1192         of_scan_flat_dt(early_init_dt_scan_root, NULL);
1193
1194         /* Setup memory, calling early_init_dt_add_memory_arch */
1195         of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1196 }
1197
1198 bool __init early_init_dt_scan(void *params)
1199 {
1200         bool status;
1201
1202         status = early_init_dt_verify(params);
1203         if (!status)
1204                 return false;
1205
1206         early_init_dt_scan_nodes();
1207         return true;
1208 }
1209
1210 /**
1211  * unflatten_device_tree - create tree of device_nodes from flat blob
1212  *
1213  * unflattens the device-tree passed by the firmware, creating the
1214  * tree of struct device_node. It also fills the "name" and "type"
1215  * pointers of the nodes so the normal device-tree walking functions
1216  * can be used.
1217  */
1218 void __init unflatten_device_tree(void)
1219 {
1220         __unflatten_device_tree(initial_boot_params, NULL, &of_root,
1221                                 early_init_dt_alloc_memory_arch, false);
1222
1223         /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1224         of_alias_scan(early_init_dt_alloc_memory_arch);
1225
1226         unittest_unflatten_overlay_base();
1227 }
1228
1229 /**
1230  * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1231  *
1232  * Copies and unflattens the device-tree passed by the firmware, creating the
1233  * tree of struct device_node. It also fills the "name" and "type"
1234  * pointers of the nodes so the normal device-tree walking functions
1235  * can be used. This should only be used when the FDT memory has not been
1236  * reserved such is the case when the FDT is built-in to the kernel init
1237  * section. If the FDT memory is reserved already then unflatten_device_tree
1238  * should be used instead.
1239  */
1240 void __init unflatten_and_copy_device_tree(void)
1241 {
1242         int size;
1243         void *dt;
1244
1245         if (!initial_boot_params) {
1246                 pr_warn("No valid device tree found, continuing without\n");
1247                 return;
1248         }
1249
1250         size = fdt_totalsize(initial_boot_params);
1251         dt = early_init_dt_alloc_memory_arch(size,
1252                                              roundup_pow_of_two(FDT_V17_SIZE));
1253
1254         if (dt) {
1255                 memcpy(dt, initial_boot_params, size);
1256                 initial_boot_params = dt;
1257         }
1258         unflatten_device_tree();
1259 }
1260
1261 #ifdef CONFIG_SYSFS
1262 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1263                                struct bin_attribute *bin_attr,
1264                                char *buf, loff_t off, size_t count)
1265 {
1266         memcpy(buf, initial_boot_params + off, count);
1267         return count;
1268 }
1269
1270 static int __init of_fdt_raw_init(void)
1271 {
1272         static struct bin_attribute of_fdt_raw_attr =
1273                 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1274
1275         if (!initial_boot_params)
1276                 return 0;
1277
1278         if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1279                                      fdt_totalsize(initial_boot_params))) {
1280                 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1281                 return 0;
1282         }
1283         of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1284         return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1285 }
1286 late_initcall(of_fdt_raw_init);
1287 #endif
1288
1289 #endif /* CONFIG_OF_EARLY_FLATTREE */