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
  28 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  29 #include <asm/page.h>
  30
  31 #include "of_private.h"
  32
  33 /*
  34  * of_fdt_limit_memory - limit the number of regions in the /memory node
  35  * @limit: maximum entries
  36  *
  37  * Adjust the flattened device tree to have at most 'limit' number of
  38  * memory entries in the /memory node. This function may be called
  39  * any time after initial_boot_param is set.
  40  */
  41 void of_fdt_limit_memory(int limit)
  42 {
  43         int memory;
  44         int len;
  45         const void *val;
  46         int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
  47         int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
  48         const __be32 *addr_prop;
  49         const __be32 *size_prop;
  50         int root_offset;
  51         int cell_size;
  52
  53         root_offset = fdt_path_offset(initial_boot_params, "/");
  54         if (root_offset < 0)
  55                 return;
  56
  57         addr_prop = fdt_getprop(initial_boot_params, root_offset,
  58                                 "#address-cells", NULL);
  59         if (addr_prop)
  60                 nr_address_cells = fdt32_to_cpu(*addr_prop);
  61
  62         size_prop = fdt_getprop(initial_boot_params, root_offset,
  63                                 "#size-cells", NULL);
  64         if (size_prop)
  65                 nr_size_cells = fdt32_to_cpu(*size_prop);
  66
  67         cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
  68
  69         memory = fdt_path_offset(initial_boot_params, "/memory");
  70         if (memory > 0) {
  71                 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
  72                 if (len > limit*cell_size) {
  73                         len = limit*cell_size;
  74                         pr_debug("Limiting number of entries to %d\n", limit);
  75                         fdt_setprop(initial_boot_params, memory, "reg", val,
  76                                         len);
  77                 }
  78         }
  79 }
  80
  81 /**
  82  * of_fdt_is_compatible - Return true if given node from the given blob has
  83  * compat in its compatible list
  84  * @blob: A device tree blob
  85  * @node: node to test
  86  * @compat: compatible string to compare with compatible list.
  87  *
  88  * On match, returns a non-zero value with smaller values returned for more
  89  * specific compatible values.
  90  */
  91 static int of_fdt_is_compatible(const void *blob,
  92                       unsigned long node, const char *compat)
  93 {
  94         const char *cp;
  95         int cplen;
  96         unsigned long l, score = 0;
  97
  98         cp = fdt_getprop(blob, node, "compatible", &cplen);
  99         if (cp == NULL)
 100                 return 0;
 101         while (cplen > 0) {
 102                 score++;
 103                 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 104                         return score;
 105                 l = strlen(cp) + 1;
 106                 cp += l;
 107                 cplen -= l;
 108         }
 109
 110         return 0;
 111 }
 112
 113 /**
 114  * of_fdt_is_big_endian - Return true if given node needs BE MMIO accesses
 115  * @blob: A device tree blob
 116  * @node: node to test
 117  *
 118  * Returns true if the node has a "big-endian" property, or if the kernel
 119  * was compiled for BE *and* the node has a "native-endian" property.
 120  * Returns false otherwise.
 121  */
 122 bool of_fdt_is_big_endian(const void *blob, unsigned long node)
 123 {
 124         if (fdt_getprop(blob, node, "big-endian", NULL))
 125                 return true;
 126         if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
 127             fdt_getprop(blob, node, "native-endian", NULL))
 128                 return true;
 129         return false;
 130 }
 131
 132 static bool of_fdt_device_is_available(const void *blob, unsigned long node)
 133 {
 134         const char *status = fdt_getprop(blob, node, "status", NULL);
 135
 136         if (!status)
 137                 return true;
 138
 139         if (!strcmp(status, "ok") || !strcmp(status, "okay"))
 140                 return true;
 141
 142         return false;
 143 }
 144
 145 /**
 146  * of_fdt_match - Return true if node matches a list of compatible values
 147  */
 148 int of_fdt_match(const void *blob, unsigned long node,
 149                  const char *const *compat)
 150 {
 151         unsigned int tmp, score = 0;
 152
 153         if (!compat)
 154                 return 0;
 155
 156         while (*compat) {
 157                 tmp = of_fdt_is_compatible(blob, node, *compat);
 158                 if (tmp && (score == 0 || (tmp < score)))
 159                         score = tmp;
 160                 compat++;
 161         }
 162
 163         return score;
 164 }
 165
 166 static void *unflatten_dt_alloc(void **mem, unsigned long size,
 167                                        unsigned long align)
 168 {
 169         void *res;
 170
 171         *mem = PTR_ALIGN(*mem, align);
 172         res = *mem;
 173         *mem += size;
 174
 175         return res;
 176 }
 177
 178 static void populate_properties(const void *blob,
 179                                 int offset,
 180                                 void **mem,
 181                                 struct device_node *np,
 182                                 const char *nodename,
 183                                 bool dryrun)
 184 {
 185         struct property *pp, **pprev = NULL;
 186         int cur;
 187         bool has_name = false;
 188
 189         pprev = &np->properties;
 190         for (cur = fdt_first_property_offset(blob, offset);
 191              cur >= 0;
 192              cur = fdt_next_property_offset(blob, cur)) {
 193                 const __be32 *val;
 194                 const char *pname;
 195                 u32 sz;
 196
 197                 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
 198                 if (!val) {
 199                         pr_warn("Cannot locate property at 0x%x\n", cur);
 200                         continue;
 201                 }
 202
 203                 if (!pname) {
 204                         pr_warn("Cannot find property name at 0x%x\n", cur);
 205                         continue;
 206                 }
 207
 208                 if (!strcmp(pname, "name"))
 209                         has_name = true;
 210
 211                 pp = unflatten_dt_alloc(mem, sizeof(struct property),
 212                                         __alignof__(struct property));
 213                 if (dryrun)
 214                         continue;
 215
 216                 /* We accept flattened tree phandles either in
 217                  * ePAPR-style "phandle" properties, or the
 218                  * legacy "linux,phandle" properties.  If both
 219                  * appear and have different values, things
 220                  * will get weird. Don't do that.
 221                  */
 222                 if (!strcmp(pname, "phandle") ||
 223                     !strcmp(pname, "linux,phandle")) {
 224                         if (!np->phandle)
 225                                 np->phandle = be32_to_cpup(val);
 226                 }
 227
 228                 /* And we process the "ibm,phandle" property
 229                  * used in pSeries dynamic device tree
 230                  * stuff
 231                  */
 232                 if (!strcmp(pname, "ibm,phandle"))
 233                         np->phandle = be32_to_cpup(val);
 234
 235                 pp->name   = (char *)pname;
 236                 pp->length = sz;
 237                 pp->value  = (__be32 *)val;
 238                 *pprev     = pp;
 239                 pprev      = &pp->next;
 240         }
 241
 242         /* With version 0x10 we may not have the name property,
 243          * recreate it here from the unit name if absent
 244          */
 245         if (!has_name) {
 246                 const char *p = nodename, *ps = p, *pa = NULL;
 247                 int len;
 248
 249                 while (*p) {
 250                         if ((*p) == '@')
 251                                 pa = p;
 252                         else if ((*p) == '/')
 253                                 ps = p + 1;
 254                         p++;
 255                 }
 256
 257                 if (pa < ps)
 258                         pa = p;
 259                 len = (pa - ps) + 1;
 260                 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
 261                                         __alignof__(struct property));
 262                 if (!dryrun) {
 263                         pp->name   = "name";
 264                         pp->length = len;
 265                         pp->value  = pp + 1;
 266                         *pprev     = pp;
 267                         pprev      = &pp->next;
 268                         memcpy(pp->value, ps, len - 1);
 269                         ((char *)pp->value)[len - 1] = 0;
 270                         pr_debug("fixed up name for %s -> %s\n",
 271                                  nodename, (char *)pp->value);
 272                 }
 273         }
 274
 275         if (!dryrun)
 276                 *pprev = NULL;
 277 }
 278
 279 static bool populate_node(const void *blob,
 280                           int offset,
 281                           void **mem,
 282                           struct device_node *dad,
 283                           struct device_node **pnp,
 284                           bool dryrun)
 285 {
 286         struct device_node *np;
 287         const char *pathp;
 288         unsigned int l, allocl;
 289
 290         pathp = fdt_get_name(blob, offset, &l);
 291         if (!pathp) {
 292                 *pnp = NULL;
 293                 return false;
 294         }
 295
 296         allocl = ++l;
 297
 298         np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
 299                                 __alignof__(struct device_node));
 300         if (!dryrun) {
 301                 char *fn;
 302                 of_node_init(np);
 303                 np->full_name = fn = ((char *)np) + sizeof(*np);
 304
 305                 memcpy(fn, pathp, l);
 306
 307                 if (dad != NULL) {
 308                         np->parent = dad;
 309                         np->sibling = dad->child;
 310                         dad->child = np;
 311                 }
 312         }
 313
 314         populate_properties(blob, offset, mem, np, pathp, dryrun);
 315         if (!dryrun) {
 316                 np->name = of_get_property(np, "name", NULL);
 317                 np->type = of_get_property(np, "device_type", NULL);
 318
 319                 if (!np->name)
 320                         np->name = "<NULL>";
 321                 if (!np->type)
 322                         np->type = "<NULL>";
 323         }
 324
 325         *pnp = np;
 326         return true;
 327 }
 328
 329 static void reverse_nodes(struct device_node *parent)
 330 {
 331         struct device_node *child, *next;
 332
 333         /* In-depth first */
 334         child = parent->child;
 335         while (child) {
 336                 reverse_nodes(child);
 337
 338                 child = child->sibling;
 339         }
 340
 341         /* Reverse the nodes in the child list */
 342         child = parent->child;
 343         parent->child = NULL;
 344         while (child) {
 345                 next = child->sibling;
 346
 347                 child->sibling = parent->child;
 348                 parent->child = child;
 349                 child = next;
 350         }
 351 }
 352
 353 /**
 354  * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
 355  * @blob: The parent device tree blob
 356  * @mem: Memory chunk to use for allocating device nodes and properties
 357  * @dad: Parent struct device_node
 358  * @nodepp: The device_node tree created by the call
 359  *
 360  * It returns the size of unflattened device tree or error code
 361  */
 362 static int unflatten_dt_nodes(const void *blob,
 363                               void *mem,
 364                               struct device_node *dad,
 365                               struct device_node **nodepp)
 366 {
 367         struct device_node *root;
 368         int offset = 0, depth = 0, initial_depth = 0;
 369 #define FDT_MAX_DEPTH   64
 370         struct device_node *nps[FDT_MAX_DEPTH];
 371         void *base = mem;
 372         bool dryrun = !base;
 373
 374         if (nodepp)
 375                 *nodepp = NULL;
 376
 377         /*
 378          * We're unflattening device sub-tree if @dad is valid. There are
 379          * possibly multiple nodes in the first level of depth. We need
 380          * set @depth to 1 to make fdt_next_node() happy as it bails
 381          * immediately when negative @depth is found. Otherwise, the device
 382          * nodes except the first one won't be unflattened successfully.
 383          */
 384         if (dad)
 385                 depth = initial_depth = 1;
 386
 387         root = dad;
 388         nps[depth] = dad;
 389
 390         for (offset = 0;
 391              offset >= 0 && depth >= initial_depth;
 392              offset = fdt_next_node(blob, offset, &depth)) {
 393                 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
 394                         continue;
 395
 396                 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
 397                     !of_fdt_device_is_available(blob, offset))
 398                         continue;
 399
 400                 if (!populate_node(blob, offset, &mem, nps[depth],
 401                                    &nps[depth+1], dryrun))
 402                         return mem - base;
 403
 404                 if (!dryrun && nodepp && !*nodepp)
 405                         *nodepp = nps[depth+1];
 406                 if (!dryrun && !root)
 407                         root = nps[depth+1];
 408         }
 409
 410         if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 411                 pr_err("Error %d processing FDT\n", offset);
 412                 return -EINVAL;
 413         }
 414
 415         /*
 416          * Reverse the child list. Some drivers assumes node order matches .dts
 417          * node order
 418          */
 419         if (!dryrun)
 420                 reverse_nodes(root);
 421
 422         return mem - base;
 423 }
 424
 425 /**
 426  * __unflatten_device_tree - create tree of device_nodes from flat blob
 427  *
 428  * unflattens a device-tree, creating the
 429  * tree of struct device_node. It also fills the "name" and "type"
 430  * pointers of the nodes so the normal device-tree walking functions
 431  * can be used.
 432  * @blob: The blob to expand
 433  * @dad: Parent device node
 434  * @mynodes: The device_node tree created by the call
 435  * @dt_alloc: An allocator that provides a virtual address to memory
 436  * for the resulting tree
 437  * @detached: if true set OF_DETACHED on @mynodes
 438  *
 439  * Returns NULL on failure or the memory chunk containing the unflattened
 440  * device tree on success.
 441  */
 442 void *__unflatten_device_tree(const void *blob,
 443                               struct device_node *dad,
 444                               struct device_node **mynodes,
 445                               void *(*dt_alloc)(u64 size, u64 align),
 446                               bool detached)
 447 {
 448         int size;
 449         void *mem;
 450
 451         pr_debug(" -> unflatten_device_tree()\n");
 452
 453         if (!blob) {
 454                 pr_debug("No device tree pointer\n");
 455                 return NULL;
 456         }
 457
 458         pr_debug("Unflattening device tree:\n");
 459         pr_debug("magic: %08x\n", fdt_magic(blob));
 460         pr_debug("size: %08x\n", fdt_totalsize(blob));
 461         pr_debug("version: %08x\n", fdt_version(blob));
 462
 463         if (fdt_check_header(blob)) {
 464                 pr_err("Invalid device tree blob header\n");
 465                 return NULL;
 466         }
 467
 468         /* First pass, scan for size */
 469         size = unflatten_dt_nodes(blob, NULL, dad, NULL);
 470         if (size < 0)
 471                 return NULL;
 472
 473         size = ALIGN(size, 4);
 474         pr_debug("  size is %d, allocating...\n", size);
 475
 476         /* Allocate memory for the expanded device tree */
 477         mem = dt_alloc(size + 4, __alignof__(struct device_node));
 478         if (!mem)
 479                 return NULL;
 480
 481         memset(mem, 0, size);
 482
 483         *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 484
 485         pr_debug("  unflattening %p...\n", mem);
 486
 487         /* Second pass, do actual unflattening */
 488         unflatten_dt_nodes(blob, mem, dad, mynodes);
 489         if (be32_to_cpup(mem + size) != 0xdeadbeef)
 490                 pr_warning("End of tree marker overwritten: %08x\n",
 491                            be32_to_cpup(mem + size));
 492
 493         if (detached && mynodes) {
 494                 of_node_set_flag(*mynodes, OF_DETACHED);
 495                 pr_debug("unflattened tree is detached\n");
 496         }
 497
 498         pr_debug(" <- unflatten_device_tree()\n");
 499         return mem;
 500 }
 501
 502 static void *kernel_tree_alloc(u64 size, u64 align)
 503 {
 504         return kzalloc(size, GFP_KERNEL);
 505 }
 506
 507 static DEFINE_MUTEX(of_fdt_unflatten_mutex);
 508
 509 /**
 510  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 511  * @blob: Flat device tree blob
 512  * @dad: Parent device node
 513  * @mynodes: The device tree created by the call
 514  *
 515  * unflattens the device-tree passed by the firmware, creating the
 516  * tree of struct device_node. It also fills the "name" and "type"
 517  * pointers of the nodes so the normal device-tree walking functions
 518  * can be used.
 519  *
 520  * Returns NULL on failure or the memory chunk containing the unflattened
 521  * device tree on success.
 522  */
 523 void *of_fdt_unflatten_tree(const unsigned long *blob,
 524                             struct device_node *dad,
 525                             struct device_node **mynodes)
 526 {
 527         void *mem;
 528
 529         mutex_lock(&of_fdt_unflatten_mutex);
 530         mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
 531                                       true);
 532         mutex_unlock(&of_fdt_unflatten_mutex);
 533
 534         return mem;
 535 }
 536 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 537
 538 /* Everything below here references initial_boot_params directly. */
 539 int __initdata dt_root_addr_cells;
 540 int __initdata dt_root_size_cells;
 541
 542 void *initial_boot_params;
 543
 544 #ifdef CONFIG_OF_EARLY_FLATTREE
 545
 546 static u32 of_fdt_crc32;
 547
 548 /**
 549  * res_mem_reserve_reg() - reserve all memory described in 'reg' property
 550  */
 551 static int __init __reserved_mem_reserve_reg(unsigned long node,
 552                                              const char *uname)
 553 {
 554         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 555         phys_addr_t base, size;
 556         int len;
 557         const __be32 *prop;
 558         int nomap, first = 1;
 559
 560         prop = of_get_flat_dt_prop(node, "reg", &len);
 561         if (!prop)
 562                 return -ENOENT;
 563
 564         if (len && len % t_len != 0) {
 565                 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 566                        uname);
 567                 return -EINVAL;
 568         }
 569
 570         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 571
 572         while (len >= t_len) {
 573                 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 574                 size = dt_mem_next_cell(dt_root_size_cells, &prop);
 575
 576                 if (size &&
 577                     early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 578                         pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 579                                 uname, &base, (unsigned long)size / SZ_1M);
 580                 else
 581                         pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 582                                 uname, &base, (unsigned long)size / SZ_1M);
 583
 584                 len -= t_len;
 585                 if (first) {
 586                         fdt_reserved_mem_save_node(node, uname, base, size);
 587                         first = 0;
 588                 }
 589         }
 590         return 0;
 591 }
 592
 593 /**
 594  * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 595  * in /reserved-memory matches the values supported by the current implementation,
 596  * also check if ranges property has been provided
 597  */
 598 static int __init __reserved_mem_check_root(unsigned long node)
 599 {
 600         const __be32 *prop;
 601
 602         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 603         if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 604                 return -EINVAL;
 605
 606         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 607         if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 608                 return -EINVAL;
 609
 610         prop = of_get_flat_dt_prop(node, "ranges", NULL);
 611         if (!prop)
 612                 return -EINVAL;
 613         return 0;
 614 }
 615
 616 /**
 617  * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 618  */
 619 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 620                                           int depth, void *data)
 621 {
 622         static int found;
 623         int err;
 624
 625         if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 626                 if (__reserved_mem_check_root(node) != 0) {
 627                         pr_err("Reserved memory: unsupported node format, ignoring\n");
 628                         /* break scan */
 629                         return 1;
 630                 }
 631                 found = 1;
 632                 /* scan next node */
 633                 return 0;
 634         } else if (!found) {
 635                 /* scan next node */
 636                 return 0;
 637         } else if (found && depth < 2) {
 638                 /* scanning of /reserved-memory has been finished */
 639                 return 1;
 640         }
 641
 642         if (!of_fdt_device_is_available(initial_boot_params, node))
 643                 return 0;
 644
 645         err = __reserved_mem_reserve_reg(node, uname);
 646         if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 647                 fdt_reserved_mem_save_node(node, uname, 0, 0);
 648
 649         /* scan next node */
 650         return 0;
 651 }
 652
 653 /**
 654  * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 655  *
 656  * This function grabs memory from early allocator for device exclusive use
 657  * defined in device tree structures. It should be called by arch specific code
 658  * once the early allocator (i.e. memblock) has been fully activated.
 659  */
 660 void __init early_init_fdt_scan_reserved_mem(void)
 661 {
 662         int n;
 663         u64 base, size;
 664
 665         if (!initial_boot_params)
 666                 return;
 667
 668         /* Process header /memreserve/ fields */
 669         for (n = 0; ; n++) {
 670                 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 671                 if (!size)
 672                         break;
 673                 early_init_dt_reserve_memory_arch(base, size, 0);
 674         }
 675
 676         of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 677         fdt_init_reserved_mem();
 678 }
 679
 680 /**
 681  * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
 682  */
 683 void __init early_init_fdt_reserve_self(void)
 684 {
 685         if (!initial_boot_params)
 686                 return;
 687
 688         /* Reserve the dtb region */
 689         early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
 690                                           fdt_totalsize(initial_boot_params),
 691                                           0);
 692 }
 693
 694 /**
 695  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 696  * @it: callback function
 697  * @data: context data pointer
 698  *
 699  * This function is used to scan the flattened device-tree, it is
 700  * used to extract the memory information at boot before we can
 701  * unflatten the tree
 702  */
 703 int __init of_scan_flat_dt(int (*it)(unsigned long node,
 704                                      const char *uname, int depth,
 705                                      void *data),
 706                            void *data)
 707 {
 708         const void *blob = initial_boot_params;
 709         const char *pathp;
 710         int offset, rc = 0, depth = -1;
 711
 712         if (!blob)
 713                 return 0;
 714
 715         for (offset = fdt_next_node(blob, -1, &depth);
 716              offset >= 0 && depth >= 0 && !rc;
 717              offset = fdt_next_node(blob, offset, &depth)) {
 718
 719                 pathp = fdt_get_name(blob, offset, NULL);
 720                 if (*pathp == '/')
 721                         pathp = kbasename(pathp);
 722                 rc = it(offset, pathp, depth, data);
 723         }
 724         return rc;
 725 }
 726
 727 /**
 728  * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
 729  * @it: callback function
 730  * @data: context data pointer
 731  *
 732  * This function is used to scan sub-nodes of a node.
 733  */
 734 int __init of_scan_flat_dt_subnodes(unsigned long parent,
 735                                     int (*it)(unsigned long node,
 736                                               const char *uname,
 737                                               void *data),
 738                                     void *data)
 739 {
 740         const void *blob = initial_boot_params;
 741         int node;
 742
 743         fdt_for_each_subnode(node, blob, parent) {
 744                 const char *pathp;
 745                 int rc;
 746
 747                 pathp = fdt_get_name(blob, node, NULL);
 748                 if (*pathp == '/')
 749                         pathp = kbasename(pathp);
 750                 rc = it(node, pathp, data);
 751                 if (rc)
 752                         return rc;
 753         }
 754         return 0;
 755 }
 756
 757 /**
 758  * of_get_flat_dt_subnode_by_name - get the subnode by given name
 759  *
 760  * @node: the parent node
 761  * @uname: the name of subnode
 762  * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
 763  */
 764
 765 int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
 766 {
 767         return fdt_subnode_offset(initial_boot_params, node, uname);
 768 }
 769
 770 /**
 771  * of_get_flat_dt_root - find the root node in the flat blob
 772  */
 773 unsigned long __init of_get_flat_dt_root(void)
 774 {
 775         return 0;
 776 }
 777
 778 /**
 779  * of_get_flat_dt_size - Return the total size of the FDT
 780  */
 781 int __init of_get_flat_dt_size(void)
 782 {
 783         return fdt_totalsize(initial_boot_params);
 784 }
 785
 786 /**
 787  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 788  *
 789  * This function can be used within scan_flattened_dt callback to get
 790  * access to properties
 791  */
 792 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 793                                        int *size)
 794 {
 795         return fdt_getprop(initial_boot_params, node, name, size);
 796 }
 797
 798 /**
 799  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 800  * @node: node to test
 801  * @compat: compatible string to compare with compatible list.
 802  */
 803 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 804 {
 805         return of_fdt_is_compatible(initial_boot_params, node, compat);
 806 }
 807
 808 /**
 809  * of_flat_dt_match - Return true if node matches a list of compatible values
 810  */
 811 int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 812 {
 813         return of_fdt_match(initial_boot_params, node, compat);
 814 }
 815
 816 /**
 817  * of_get_flat_dt_prop - Given a node in the flat blob, return the phandle
 818  */
 819 uint32_t __init of_get_flat_dt_phandle(unsigned long node)
 820 {
 821         return fdt_get_phandle(initial_boot_params, node);
 822 }
 823
 824 struct fdt_scan_status {
 825         const char *name;
 826         int namelen;
 827         int depth;
 828         int found;
 829         int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 830         void *data;
 831 };
 832
 833 const char * __init of_flat_dt_get_machine_name(void)
 834 {
 835         const char *name;
 836         unsigned long dt_root = of_get_flat_dt_root();
 837
 838         name = of_get_flat_dt_prop(dt_root, "model", NULL);
 839         if (!name)
 840                 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 841         return name;
 842 }
 843
 844 /**
 845  * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 846  *
 847  * @default_match: A machine specific ptr to return in case of no match.
 848  * @get_next_compat: callback function to return next compatible match table.
 849  *
 850  * Iterate through machine match tables to find the best match for the machine
 851  * compatible string in the FDT.
 852  */
 853 const void * __init of_flat_dt_match_machine(const void *default_match,
 854                 const void * (*get_next_compat)(const char * const**))
 855 {
 856         const void *data = NULL;
 857         const void *best_data = default_match;
 858         const char *const *compat;
 859         unsigned long dt_root;
 860         unsigned int best_score = ~1, score = 0;
 861
 862         dt_root = of_get_flat_dt_root();
 863         while ((data = get_next_compat(&compat))) {
 864                 score = of_flat_dt_match(dt_root, compat);
 865                 if (score > 0 && score < best_score) {
 866                         best_data = data;
 867                         best_score = score;
 868                 }
 869         }
 870         if (!best_data) {
 871                 const char *prop;
 872                 int size;
 873
 874                 pr_err("\n unrecognized device tree list:\n[ ");
 875
 876                 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 877                 if (prop) {
 878                         while (size > 0) {
 879                                 printk("'%s' ", prop);
 880                                 size -= strlen(prop) + 1;
 881                                 prop += strlen(prop) + 1;
 882                         }
 883                 }
 884                 printk("]\n\n");
 885                 return NULL;
 886         }
 887
 888         pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 889
 890         return best_data;
 891 }
 892
 893 #ifdef CONFIG_BLK_DEV_INITRD
 894 static void __early_init_dt_declare_initrd(unsigned long start,
 895                                            unsigned long end)
 896 {
 897         /* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is
 898          * enabled since __va() is called too early. ARM64 does make use
 899          * of phys_initrd_start/phys_initrd_size so we can skip this
 900          * conversion.
 901          */
 902         if (!IS_ENABLED(CONFIG_ARM64)) {
 903                 initrd_start = (unsigned long)__va(start);
 904                 initrd_end = (unsigned long)__va(end);
 905                 initrd_below_start_ok = 1;
 906         }
 907 }
 908
 909 /**
 910  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 911  * @node: reference to node containing initrd location ('chosen')
 912  */
 913 static void __init early_init_dt_check_for_initrd(unsigned long node)
 914 {
 915         u64 start, end;
 916         int len;
 917         const __be32 *prop;
 918
 919         pr_debug("Looking for initrd properties... ");
 920
 921         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 922         if (!prop)
 923                 return;
 924         start = of_read_number(prop, len/4);
 925
 926         prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 927         if (!prop)
 928                 return;
 929         end = of_read_number(prop, len/4);
 930
 931         __early_init_dt_declare_initrd(start, end);
 932         phys_initrd_start = start;
 933         phys_initrd_size = end - start;
 934
 935         pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 936                  (unsigned long long)start, (unsigned long long)end);
 937 }
 938 #else
 939 static inline void early_init_dt_check_for_initrd(unsigned long node)
 940 {
 941 }
 942 #endif /* CONFIG_BLK_DEV_INITRD */
 943
 944 #ifdef CONFIG_SERIAL_EARLYCON
 945
 946 int __init early_init_dt_scan_chosen_stdout(void)
 947 {
 948         int offset;
 949         const char *p, *q, *options = NULL;
 950         int l;
 951         const struct earlycon_id **p_match;
 952         const void *fdt = initial_boot_params;
 953
 954         offset = fdt_path_offset(fdt, "/chosen");
 955         if (offset < 0)
 956                 offset = fdt_path_offset(fdt, "/chosen@0");
 957         if (offset < 0)
 958                 return -ENOENT;
 959
 960         p = fdt_getprop(fdt, offset, "stdout-path", &l);
 961         if (!p)
 962                 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 963         if (!p || !l)
 964                 return -ENOENT;
 965
 966         q = strchrnul(p, ':');
 967         if (*q != '\0')
 968                 options = q + 1;
 969         l = q - p;
 970
 971         /* Get the node specified by stdout-path */
 972         offset = fdt_path_offset_namelen(fdt, p, l);
 973         if (offset < 0) {
 974                 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
 975                 return 0;
 976         }
 977
 978         for (p_match = __earlycon_table; p_match < __earlycon_table_end;
 979              p_match++) {
 980                 const struct earlycon_id *match = *p_match;
 981
 982                 if (!match->compatible[0])
 983                         continue;
 984
 985                 if (fdt_node_check_compatible(fdt, offset, match->compatible))
 986                         continue;
 987
 988                 of_setup_earlycon(match, offset, options);
 989                 return 0;
 990         }
 991         return -ENODEV;
 992 }
 993 #endif
 994
 995 /**
 996  * early_init_dt_scan_root - fetch the top level address and size cells
 997  */
 998 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 999                                    int depth, void *data)
1000 {
1001         const __be32 *prop;
1002
1003         if (depth != 0)
1004                 return 0;
1005
1006         dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
1007         dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
1008
1009         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
1010         if (prop)
1011                 dt_root_size_cells = be32_to_cpup(prop);
1012         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
1013
1014         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
1015         if (prop)
1016                 dt_root_addr_cells = be32_to_cpup(prop);
1017         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
1018
1019         /* break now */
1020         return 1;
1021 }
1022
1023 u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
1024 {
1025         const __be32 *p = *cellp;
1026
1027         *cellp = p + s;
1028         return of_read_number(p, s);
1029 }
1030
1031 /**
1032  * early_init_dt_scan_memory - Look for and parse memory nodes
1033  */
1034 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
1035                                      int depth, void *data)
1036 {
1037         const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
1038         const __be32 *reg, *endp;
1039         int l;
1040         bool hotpluggable;
1041
1042         /* We are scanning "memory" nodes only */
1043         if (type == NULL || strcmp(type, "memory") != 0)
1044                 return 0;
1045
1046         reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1047         if (reg == NULL)
1048                 reg = of_get_flat_dt_prop(node, "reg", &l);
1049         if (reg == NULL)
1050                 return 0;
1051
1052         endp = reg + (l / sizeof(__be32));
1053         hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1054
1055         pr_debug("memory scan node %s, reg size %d,\n", uname, l);
1056
1057         while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1058                 u64 base, size;
1059
1060                 base = dt_mem_next_cell(dt_root_addr_cells, &reg);
1061                 size = dt_mem_next_cell(dt_root_size_cells, &reg);
1062
1063                 if (size == 0)
1064                         continue;
1065                 pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
1066                     (unsigned long long)size);
1067
1068                 early_init_dt_add_memory_arch(base, size);
1069
1070                 if (!hotpluggable)
1071                         continue;
1072
1073                 if (early_init_dt_mark_hotplug_memory_arch(base, size))
1074                         pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1075                                 base, base + size);
1076         }
1077
1078         return 0;
1079 }
1080
1081 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
1082                                      int depth, void *data)
1083 {
1084         int l;
1085         const char *p;
1086
1087         pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
1088
1089         if (depth != 1 || !data ||
1090             (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
1091                 return 0;
1092
1093         early_init_dt_check_for_initrd(node);
1094
1095         /* Retrieve command line */
1096         p = of_get_flat_dt_prop(node, "bootargs", &l);
1097         if (p != NULL && l > 0)
1098                 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
1099
1100         /*
1101          * CONFIG_CMDLINE is meant to be a default in case nothing else
1102          * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1103          * is set in which case we override whatever was found earlier.
1104          */
1105 #ifdef CONFIG_CMDLINE
1106 #if defined(CONFIG_CMDLINE_EXTEND)
1107         strlcat(data, " ", COMMAND_LINE_SIZE);
1108         strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1109 #elif defined(CONFIG_CMDLINE_FORCE)
1110         strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1111 #else
1112         /* No arguments from boot loader, use kernel's  cmdl*/
1113         if (!((char *)data)[0])
1114                 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1115 #endif
1116 #endif /* CONFIG_CMDLINE */
1117
1118         pr_debug("Command line is: %s\n", (char*)data);
1119
1120         /* break now */
1121         return 1;
1122 }
1123
1124 #ifndef MIN_MEMBLOCK_ADDR
1125 #define MIN_MEMBLOCK_ADDR       __pa(PAGE_OFFSET)
1126 #endif
1127 #ifndef MAX_MEMBLOCK_ADDR
1128 #define MAX_MEMBLOCK_ADDR       ((phys_addr_t)~0)
1129 #endif
1130
1131 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1132 {
1133         const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1134
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
1141         if (!PAGE_ALIGNED(base)) {
1142                 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1143                 base = PAGE_ALIGN(base);
1144         }
1145         size &= PAGE_MASK;
1146
1147         if (base > MAX_MEMBLOCK_ADDR) {
1148                 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1149                                 base, base + size);
1150                 return;
1151         }
1152
1153         if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1154                 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1155                                 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1156                 size = MAX_MEMBLOCK_ADDR - base + 1;
1157         }
1158
1159         if (base + size < phys_offset) {
1160                 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1161                            base, base + size);
1162                 return;
1163         }
1164         if (base < phys_offset) {
1165                 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1166                            base, phys_offset);
1167                 size -= phys_offset - base;
1168                 base = phys_offset;
1169         }
1170         memblock_add(base, size);
1171 }
1172
1173 int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1174 {
1175         return memblock_mark_hotplug(base, size);
1176 }
1177
1178 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1179                                         phys_addr_t size, bool nomap)
1180 {
1181         if (nomap)
1182                 return memblock_remove(base, size);
1183         return memblock_reserve(base, size);
1184 }
1185
1186 static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1187 {
1188         return memblock_alloc(size, align);
1189 }
1190
1191 bool __init early_init_dt_verify(void *params)
1192 {
1193         if (!params)
1194                 return false;
1195
1196         /* check device tree validity */
1197         if (fdt_check_header(params))
1198                 return false;
1199
1200         /* Setup flat device-tree pointer */
1201         initial_boot_params = params;
1202         of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1203                                 fdt_totalsize(initial_boot_params));
1204         return true;
1205 }
1206
1207
1208 void __init early_init_dt_scan_nodes(void)
1209 {
1210         int rc = 0;
1211
1212         /* Retrieve various information from the /chosen node */
1213         rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1214         if (!rc)
1215                 pr_warn("No chosen node found, continuing without\n");
1216
1217         /* Initialize {size,address}-cells info */
1218         of_scan_flat_dt(early_init_dt_scan_root, NULL);
1219
1220         /* Setup memory, calling early_init_dt_add_memory_arch */
1221         of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1222 }
1223
1224 bool __init early_init_dt_scan(void *params)
1225 {
1226         bool status;
1227
1228         status = early_init_dt_verify(params);
1229         if (!status)
1230                 return false;
1231
1232         early_init_dt_scan_nodes();
1233         return true;
1234 }
1235
1236 /**
1237  * unflatten_device_tree - create tree of device_nodes from flat blob
1238  *
1239  * unflattens the device-tree passed by the firmware, creating the
1240  * tree of struct device_node. It also fills the "name" and "type"
1241  * pointers of the nodes so the normal device-tree walking functions
1242  * can be used.
1243  */
1244 void __init unflatten_device_tree(void)
1245 {
1246         __unflatten_device_tree(initial_boot_params, NULL, &of_root,
1247                                 early_init_dt_alloc_memory_arch, false);
1248
1249         /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1250         of_alias_scan(early_init_dt_alloc_memory_arch);
1251
1252         unittest_unflatten_overlay_base();
1253 }
1254
1255 /**
1256  * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1257  *
1258  * Copies and unflattens the device-tree passed by the firmware, creating the
1259  * tree of struct device_node. It also fills the "name" and "type"
1260  * pointers of the nodes so the normal device-tree walking functions
1261  * can be used. This should only be used when the FDT memory has not been
1262  * reserved such is the case when the FDT is built-in to the kernel init
1263  * section. If the FDT memory is reserved already then unflatten_device_tree
1264  * should be used instead.
1265  */
1266 void __init unflatten_and_copy_device_tree(void)
1267 {
1268         int size;
1269         void *dt;
1270
1271         if (!initial_boot_params) {
1272                 pr_warn("No valid device tree found, continuing without\n");
1273                 return;
1274         }
1275
1276         size = fdt_totalsize(initial_boot_params);
1277         dt = early_init_dt_alloc_memory_arch(size,
1278                                              roundup_pow_of_two(FDT_V17_SIZE));
1279
1280         if (dt) {
1281                 memcpy(dt, initial_boot_params, size);
1282                 initial_boot_params = dt;
1283         }
1284         unflatten_device_tree();
1285 }
1286
1287 #ifdef CONFIG_SYSFS
1288 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1289                                struct bin_attribute *bin_attr,
1290                                char *buf, loff_t off, size_t count)
1291 {
1292         memcpy(buf, initial_boot_params + off, count);
1293         return count;
1294 }
1295
1296 static int __init of_fdt_raw_init(void)
1297 {
1298         static struct bin_attribute of_fdt_raw_attr =
1299                 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1300
1301         if (!initial_boot_params)
1302                 return 0;
1303
1304         if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1305                                      fdt_totalsize(initial_boot_params))) {
1306                 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1307                 return 0;
1308         }
1309         of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1310         return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1311 }
1312 late_initcall(of_fdt_raw_init);
1313 #endif
1314
1315 #endif /* CONFIG_OF_EARLY_FLATTREE */