drivers/of/fdt.c

   1 /*
   2  * Functions for working with the Flattened Device Tree data format
   3  *
   4  * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
   5  * benh@kernel.crashing.org
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  */
  11
  12 #define pr_fmt(fmt)     "OF: fdt: " fmt
  13
  14 #include <linux/crc32.h>
  15 #include <linux/kernel.h>
  16 #include <linux/initrd.h>
  17 #include <linux/memblock.h>
  18 #include <linux/mutex.h>
  19 #include <linux/of.h>
  20 #include <linux/of_fdt.h>
  21 #include <linux/of_reserved_mem.h>
  22 #include <linux/sizes.h>
  23 #include <linux/string.h>
  24 #include <linux/errno.h>
  25 #include <linux/slab.h>
  26 #include <linux/libfdt.h>
  27 #include <linux/debugfs.h>
  28 #include <linux/serial_core.h>
  29 #include <linux/sysfs.h>
  30
  31 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  32 #include <asm/page.h>
  33
  34 #include "of_private.h"
  35
  36 /*
  37  * of_fdt_limit_memory - limit the number of regions in the /memory node
  38  * @limit: maximum entries
  39  *
  40  * Adjust the flattened device tree to have at most 'limit' number of
  41  * memory entries in the /memory node. This function may be called
  42  * any time after initial_boot_param is set.
  43  */
  44 void of_fdt_limit_memory(int limit)
  45 {
  46         int memory;
  47         int len;
  48         const void *val;
  49         int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
  50         int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
  51         const __be32 *addr_prop;
  52         const __be32 *size_prop;
  53         int root_offset;
  54         int cell_size;
  55
  56         root_offset = fdt_path_offset(initial_boot_params, "/");
  57         if (root_offset < 0)
  58                 return;
  59
  60         addr_prop = fdt_getprop(initial_boot_params, root_offset,
  61                                 "#address-cells", NULL);
  62         if (addr_prop)
  63                 nr_address_cells = fdt32_to_cpu(*addr_prop);
  64
  65         size_prop = fdt_getprop(initial_boot_params, root_offset,
  66                                 "#size-cells", NULL);
  67         if (size_prop)
  68                 nr_size_cells = fdt32_to_cpu(*size_prop);
  69
  70         cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
  71
  72         memory = fdt_path_offset(initial_boot_params, "/memory");
  73         if (memory > 0) {
  74                 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
  75                 if (len > limit*cell_size) {
  76                         len = limit*cell_size;
  77                         pr_debug("Limiting number of entries to %d\n", limit);
  78                         fdt_setprop(initial_boot_params, memory, "reg", val,
  79                                         len);
  80                 }
  81         }
  82 }
  83
  84 /**
  85  * of_fdt_is_compatible - Return true if given node from the given blob has
  86  * compat in its compatible list
  87  * @blob: A device tree blob
  88  * @node: node to test
  89  * @compat: compatible string to compare with compatible list.
  90  *
  91  * On match, returns a non-zero value with smaller values returned for more
  92  * specific compatible values.
  93  */
  94 static int of_fdt_is_compatible(const void *blob,
  95                       unsigned long node, const char *compat)
  96 {
  97         const char *cp;
  98         int cplen;
  99         unsigned long l, score = 0;
 100
 101         cp = fdt_getprop(blob, node, "compatible", &cplen);
 102         if (cp == NULL)
 103                 return 0;
 104         while (cplen > 0) {
 105                 score++;
 106                 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 107                         return score;
 108                 l = strlen(cp) + 1;
 109                 cp += l;
 110                 cplen -= l;
 111         }
 112
 113         return 0;
 114 }
 115
 116 /**
 117  * of_fdt_is_big_endian - Return true if given node needs BE MMIO accesses
 118  * @blob: A device tree blob
 119  * @node: node to test
 120  *
 121  * Returns true if the node has a "big-endian" property, or if the kernel
 122  * was compiled for BE *and* the node has a "native-endian" property.
 123  * Returns false otherwise.
 124  */
 125 bool of_fdt_is_big_endian(const void *blob, unsigned long node)
 126 {
 127         if (fdt_getprop(blob, node, "big-endian", NULL))
 128                 return true;
 129         if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
 130             fdt_getprop(blob, node, "native-endian", NULL))
 131                 return true;
 132         return false;
 133 }
 134
 135 static bool of_fdt_device_is_available(const void *blob, unsigned long node)
 136 {
 137         const char *status = fdt_getprop(blob, node, "status", NULL);
 138
 139         if (!status)
 140                 return true;
 141
 142         if (!strcmp(status, "ok") || !strcmp(status, "okay"))
 143                 return true;
 144
 145         return false;
 146 }
 147
 148 /**
 149  * of_fdt_match - Return true if node matches a list of compatible values
 150  */
 151 int of_fdt_match(const void *blob, unsigned long node,
 152                  const char *const *compat)
 153 {
 154         unsigned int tmp, score = 0;
 155
 156         if (!compat)
 157                 return 0;
 158
 159         while (*compat) {
 160                 tmp = of_fdt_is_compatible(blob, node, *compat);
 161                 if (tmp && (score == 0 || (tmp < score)))
 162                         score = tmp;
 163                 compat++;
 164         }
 165
 166         return score;
 167 }
 168
 169 static void *unflatten_dt_alloc(void **mem, unsigned long size,
 170                                        unsigned long align)
 171 {
 172         void *res;
 173
 174         *mem = PTR_ALIGN(*mem, align);
 175         res = *mem;
 176         *mem += size;
 177
 178         return res;
 179 }
 180
 181 static void populate_properties(const void *blob,
 182                                 int offset,
 183                                 void **mem,
 184                                 struct device_node *np,
 185                                 const char *nodename,
 186                                 bool dryrun)
 187 {
 188         struct property *pp, **pprev = NULL;
 189         int cur;
 190         bool has_name = false;
 191
 192         pprev = &np->properties;
 193         for (cur = fdt_first_property_offset(blob, offset);
 194              cur >= 0;
 195              cur = fdt_next_property_offset(blob, cur)) {
 196                 const __be32 *val;
 197                 const char *pname;
 198                 u32 sz;
 199
 200                 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
 201                 if (!val) {
 202                         pr_warn("Cannot locate property at 0x%x\n", cur);
 203                         continue;
 204                 }
 205
 206                 if (!pname) {
 207                         pr_warn("Cannot find property name at 0x%x\n", cur);
 208                         continue;
 209                 }
 210
 211                 if (!strcmp(pname, "name"))
 212                         has_name = true;
 213
 214                 pp = unflatten_dt_alloc(mem, sizeof(struct property),
 215                                         __alignof__(struct property));
 216                 if (dryrun)
 217                         continue;
 218
 219                 /* We accept flattened tree phandles either in
 220                  * ePAPR-style "phandle" properties, or the
 221                  * legacy "linux,phandle" properties.  If both
 222                  * appear and have different values, things
 223                  * will get weird. Don't do that.
 224                  */
 225                 if (!strcmp(pname, "phandle") ||
 226                     !strcmp(pname, "linux,phandle")) {
 227                         if (!np->phandle)
 228                                 np->phandle = be32_to_cpup(val);
 229                 }
 230
 231                 /* And we process the "ibm,phandle" property
 232                  * used in pSeries dynamic device tree
 233                  * stuff
 234                  */
 235                 if (!strcmp(pname, "ibm,phandle"))
 236                         np->phandle = be32_to_cpup(val);
 237
 238                 pp->name   = (char *)pname;
 239                 pp->length = sz;
 240                 pp->value  = (__be32 *)val;
 241                 *pprev     = pp;
 242                 pprev      = &pp->next;
 243         }
 244
 245         /* With version 0x10 we may not have the name property,
 246          * recreate it here from the unit name if absent
 247          */
 248         if (!has_name) {
 249                 const char *p = nodename, *ps = p, *pa = NULL;
 250                 int len;
 251
 252                 while (*p) {
 253                         if ((*p) == '@')
 254                                 pa = p;
 255                         else if ((*p) == '/')
 256                                 ps = p + 1;
 257                         p++;
 258                 }
 259
 260                 if (pa < ps)
 261                         pa = p;
 262                 len = (pa - ps) + 1;
 263                 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
 264                                         __alignof__(struct property));
 265                 if (!dryrun) {
 266                         pp->name   = "name";
 267                         pp->length = len;
 268                         pp->value  = pp + 1;
 269                         *pprev     = pp;
 270                         pprev      = &pp->next;
 271                         memcpy(pp->value, ps, len - 1);
 272                         ((char *)pp->value)[len - 1] = 0;
 273                         pr_debug("fixed up name for %s -> %s\n",
 274                                  nodename, (char *)pp->value);
 275                 }
 276         }
 277
 278         if (!dryrun)
 279                 *pprev = NULL;
 280 }
 281
 282 static bool populate_node(const void *blob,
 283                           int offset,
 284                           void **mem,
 285                           struct device_node *dad,
 286                           struct device_node **pnp,
 287                           bool dryrun)
 288 {
 289         struct device_node *np;
 290         const char *pathp;
 291         unsigned int l, allocl;
 292
 293         pathp = fdt_get_name(blob, offset, &l);
 294         if (!pathp) {
 295                 *pnp = NULL;
 296                 return false;
 297         }
 298
 299         allocl = ++l;
 300
 301         np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
 302                                 __alignof__(struct device_node));
 303         if (!dryrun) {
 304                 char *fn;
 305                 of_node_init(np);
 306                 np->full_name = fn = ((char *)np) + sizeof(*np);
 307
 308                 memcpy(fn, pathp, l);
 309
 310                 if (dad != NULL) {
 311                         np->parent = dad;
 312                         np->sibling = dad->child;
 313                         dad->child = np;
 314                 }
 315         }
 316
 317         populate_properties(blob, offset, mem, np, pathp, dryrun);
 318         if (!dryrun) {
 319                 np->name = of_get_property(np, "name", NULL);
 320                 np->type = of_get_property(np, "device_type", NULL);
 321
 322                 if (!np->name)
 323                         np->name = "<NULL>";
 324                 if (!np->type)
 325                         np->type = "<NULL>";
 326         }
 327
 328         *pnp = np;
 329         return true;
 330 }
 331
 332 static void reverse_nodes(struct device_node *parent)
 333 {
 334         struct device_node *child, *next;
 335
 336         /* In-depth first */
 337         child = parent->child;
 338         while (child) {
 339                 reverse_nodes(child);
 340
 341                 child = child->sibling;
 342         }
 343
 344         /* Reverse the nodes in the child list */
 345         child = parent->child;
 346         parent->child = NULL;
 347         while (child) {
 348                 next = child->sibling;
 349
 350                 child->sibling = parent->child;
 351                 parent->child = child;
 352                 child = next;
 353         }
 354 }
 355
 356 /**
 357  * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
 358  * @blob: The parent device tree blob
 359  * @mem: Memory chunk to use for allocating device nodes and properties
 360  * @dad: Parent struct device_node
 361  * @nodepp: The device_node tree created by the call
 362  *
 363  * It returns the size of unflattened device tree or error code
 364  */
 365 static int unflatten_dt_nodes(const void *blob,
 366                               void *mem,
 367                               struct device_node *dad,
 368                               struct device_node **nodepp)
 369 {
 370         struct device_node *root;
 371         int offset = 0, depth = 0, initial_depth = 0;
 372 #define FDT_MAX_DEPTH   64
 373         struct device_node *nps[FDT_MAX_DEPTH];
 374         void *base = mem;
 375         bool dryrun = !base;
 376
 377         if (nodepp)
 378                 *nodepp = NULL;
 379
 380         /*
 381          * We're unflattening device sub-tree if @dad is valid. There are
 382          * possibly multiple nodes in the first level of depth. We need
 383          * set @depth to 1 to make fdt_next_node() happy as it bails
 384          * immediately when negative @depth is found. Otherwise, the device
 385          * nodes except the first one won't be unflattened successfully.
 386          */
 387         if (dad)
 388                 depth = initial_depth = 1;
 389
 390         root = dad;
 391         nps[depth] = dad;
 392
 393         for (offset = 0;
 394              offset >= 0 && depth >= initial_depth;
 395              offset = fdt_next_node(blob, offset, &depth)) {
 396                 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
 397                         continue;
 398
 399                 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
 400                     !of_fdt_device_is_available(blob, offset))
 401                         continue;
 402
 403                 if (!populate_node(blob, offset, &mem, nps[depth],
 404                                    &nps[depth+1], dryrun))
 405                         return mem - base;
 406
 407                 if (!dryrun && nodepp && !*nodepp)
 408                         *nodepp = nps[depth+1];
 409                 if (!dryrun && !root)
 410                         root = nps[depth+1];
 411         }
 412
 413         if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 414                 pr_err("Error %d processing FDT\n", offset);
 415                 return -EINVAL;
 416         }
 417
 418         /*
 419          * Reverse the child list. Some drivers assumes node order matches .dts
 420          * node order
 421          */
 422         if (!dryrun)
 423                 reverse_nodes(root);
 424
 425         return mem - base;
 426 }
 427
 428 /**
 429  * __unflatten_device_tree - create tree of device_nodes from flat blob
 430  *
 431  * unflattens a device-tree, creating the
 432  * tree of struct device_node. It also fills the "name" and "type"
 433  * pointers of the nodes so the normal device-tree walking functions
 434  * can be used.
 435  * @blob: The blob to expand
 436  * @dad: Parent device node
 437  * @mynodes: The device_node tree created by the call
 438  * @dt_alloc: An allocator that provides a virtual address to memory
 439  * for the resulting tree
 440  * @detached: if true set OF_DETACHED on @mynodes
 441  *
 442  * Returns NULL on failure or the memory chunk containing the unflattened
 443  * device tree on success.
 444  */
 445 void *__unflatten_device_tree(const void *blob,
 446                               struct device_node *dad,
 447                               struct device_node **mynodes,
 448                               void *(*dt_alloc)(u64 size, u64 align),
 449                               bool detached)
 450 {
 451         int size;
 452         void *mem;
 453
 454         pr_debug(" -> unflatten_device_tree()\n");
 455
 456         if (!blob) {
 457                 pr_debug("No device tree pointer\n");
 458                 return NULL;
 459         }
 460
 461         pr_debug("Unflattening device tree:\n");
 462         pr_debug("magic: %08x\n", fdt_magic(blob));
 463         pr_debug("size: %08x\n", fdt_totalsize(blob));
 464         pr_debug("version: %08x\n", fdt_version(blob));
 465
 466         if (fdt_check_header(blob)) {
 467                 pr_err("Invalid device tree blob header\n");
 468                 return NULL;
 469         }
 470
 471         /* First pass, scan for size */
 472         size = unflatten_dt_nodes(blob, NULL, dad, NULL);
 473         if (size < 0)
 474                 return NULL;
 475
 476         size = ALIGN(size, 4);
 477         pr_debug("  size is %d, allocating...\n", size);
 478
 479         /* Allocate memory for the expanded device tree */
 480         mem = dt_alloc(size + 4, __alignof__(struct device_node));
 481         if (!mem)
 482                 return NULL;
 483
 484         memset(mem, 0, size);
 485
 486         *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 487
 488         pr_debug("  unflattening %p...\n", mem);
 489
 490         /* Second pass, do actual unflattening */
 491         unflatten_dt_nodes(blob, mem, dad, mynodes);
 492         if (be32_to_cpup(mem + size) != 0xdeadbeef)
 493                 pr_warning("End of tree marker overwritten: %08x\n",
 494                            be32_to_cpup(mem + size));
 495
 496         if (detached && mynodes) {
 497                 of_node_set_flag(*mynodes, OF_DETACHED);
 498                 pr_debug("unflattened tree is detached\n");
 499         }
 500
 501         pr_debug(" <- unflatten_device_tree()\n");
 502         return mem;
 503 }
 504
 505 static void *kernel_tree_alloc(u64 size, u64 align)
 506 {
 507         return kzalloc(size, GFP_KERNEL);
 508 }
 509
 510 static DEFINE_MUTEX(of_fdt_unflatten_mutex);
 511
 512 /**
 513  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 514  * @blob: Flat device tree blob
 515  * @dad: Parent device node
 516  * @mynodes: The device tree created by the call
 517  *
 518  * unflattens the device-tree passed by the firmware, creating the
 519  * tree of struct device_node. It also fills the "name" and "type"
 520  * pointers of the nodes so the normal device-tree walking functions
 521  * can be used.
 522  *
 523  * Returns NULL on failure or the memory chunk containing the unflattened
 524  * device tree on success.
 525  */
 526 void *of_fdt_unflatten_tree(const unsigned long *blob,
 527                             struct device_node *dad,
 528                             struct device_node **mynodes)
 529 {
 530         void *mem;
 531
 532         mutex_lock(&of_fdt_unflatten_mutex);
 533         mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
 534                                       true);
 535         mutex_unlock(&of_fdt_unflatten_mutex);
 536
 537         return mem;
 538 }
 539 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 540
 541 /* Everything below here references initial_boot_params directly. */
 542 int __initdata dt_root_addr_cells;
 543 int __initdata dt_root_size_cells;
 544
 545 void *initial_boot_params;
 546
 547 #ifdef CONFIG_OF_EARLY_FLATTREE
 548
 549 static u32 of_fdt_crc32;
 550
 551 /**
 552  * res_mem_reserve_reg() - reserve all memory described in 'reg' property
 553  */
 554 static int __init __reserved_mem_reserve_reg(unsigned long node,
 555                                              const char *uname)
 556 {
 557         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 558         phys_addr_t base, size;
 559         int len;
 560         const __be32 *prop;
 561         int nomap, first = 1;
 562
 563         prop = of_get_flat_dt_prop(node, "reg", &len);
 564         if (!prop)
 565                 return -ENOENT;
 566
 567         if (len && len % t_len != 0) {
 568                 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 569                        uname);
 570                 return -EINVAL;
 571         }
 572
 573         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 574
 575         while (len >= t_len) {
 576                 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 577                 size = dt_mem_next_cell(dt_root_size_cells, &prop);
 578
 579                 if (size &&
 580                     early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 581                         pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 582                                 uname, &base, (unsigned long)size / SZ_1M);
 583                 else
 584                         pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 585                                 uname, &base, (unsigned long)size / SZ_1M);
 586
 587                 len -= t_len;
 588                 if (first) {
 589                         fdt_reserved_mem_save_node(node, uname, base, size);
 590                         first = 0;
 591                 }
 592         }
 593         return 0;
 594 }
 595
 596 /**
 597  * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 598  * in /reserved-memory matches the values supported by the current implementation,
 599  * also check if ranges property has been provided
 600  */
 601 static int __init __reserved_mem_check_root(unsigned long node)
 602 {
 603         const __be32 *prop;
 604
 605         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 606         if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 607                 return -EINVAL;
 608
 609         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 610         if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 611                 return -EINVAL;
 612
 613         prop = of_get_flat_dt_prop(node, "ranges", NULL);
 614         if (!prop)
 615                 return -EINVAL;
 616         return 0;
 617 }
 618
 619 /**
 620  * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 621  */
 622 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 623                                           int depth, void *data)
 624 {
 625         static int found;
 626         int err;
 627
 628         if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 629                 if (__reserved_mem_check_root(node) != 0) {
 630                         pr_err("Reserved memory: unsupported node format, ignoring\n");
 631                         /* break scan */
 632                         return 1;
 633                 }
 634                 found = 1;
 635                 /* scan next node */
 636                 return 0;
 637         } else if (!found) {
 638                 /* scan next node */
 639                 return 0;
 640         } else if (found && depth < 2) {
 641                 /* scanning of /reserved-memory has been finished */
 642                 return 1;
 643         }
 644
 645         if (!of_fdt_device_is_available(initial_boot_params, node))
 646                 return 0;
 647
 648         err = __reserved_mem_reserve_reg(node, uname);
 649         if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 650                 fdt_reserved_mem_save_node(node, uname, 0, 0);
 651
 652         /* scan next node */
 653         return 0;
 654 }
 655
 656 /**
 657  * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 658  *
 659  * This function grabs memory from early allocator for device exclusive use
 660  * defined in device tree structures. It should be called by arch specific code
 661  * once the early allocator (i.e. memblock) has been fully activated.
 662  */
 663 void __init early_init_fdt_scan_reserved_mem(void)
 664 {
 665         int n;
 666         u64 base, size;
 667
 668         if (!initial_boot_params)
 669                 return;
 670
 671         /* Process header /memreserve/ fields */
 672         for (n = 0; ; n++) {
 673                 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 674                 if (!size)
 675                         break;
 676                 early_init_dt_reserve_memory_arch(base, size, 0);
 677         }
 678
 679         of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 680         fdt_init_reserved_mem();
 681 }
 682
 683 /**
 684  * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
 685  */
 686 void __init early_init_fdt_reserve_self(void)
 687 {
 688         if (!initial_boot_params)
 689                 return;
 690
 691         /* Reserve the dtb region */
 692         early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
 693                                           fdt_totalsize(initial_boot_params),
 694                                           0);
 695 }
 696
 697 /**
 698  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 699  * @it: callback function
 700  * @data: context data pointer
 701  *
 702  * This function is used to scan the flattened device-tree, it is
 703  * used to extract the memory information at boot before we can
 704  * unflatten the tree
 705  */
 706 int __init of_scan_flat_dt(int (*it)(unsigned long node,
 707                                      const char *uname, int depth,
 708                                      void *data),
 709                            void *data)
 710 {
 711         const void *blob = initial_boot_params;
 712         const char *pathp;
 713         int offset, rc = 0, depth = -1;
 714
 715         if (!blob)
 716                 return 0;
 717
 718         for (offset = fdt_next_node(blob, -1, &depth);
 719              offset >= 0 && depth >= 0 && !rc;
 720              offset = fdt_next_node(blob, offset, &depth)) {
 721
 722                 pathp = fdt_get_name(blob, offset, NULL);
 723                 if (*pathp == '/')
 724                         pathp = kbasename(pathp);
 725                 rc = it(offset, pathp, depth, data);
 726         }
 727         return rc;
 728 }
 729
 730 /**
 731  * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
 732  * @it: callback function
 733  * @data: context data pointer
 734  *
 735  * This function is used to scan sub-nodes of a node.
 736  */
 737 int __init of_scan_flat_dt_subnodes(unsigned long parent,
 738                                     int (*it)(unsigned long node,
 739                                               const char *uname,
 740                                               void *data),
 741                                     void *data)
 742 {
 743         const void *blob = initial_boot_params;
 744         int node;
 745
 746         fdt_for_each_subnode(node, blob, parent) {
 747                 const char *pathp;
 748                 int rc;
 749
 750                 pathp = fdt_get_name(blob, node, NULL);
 751                 if (*pathp == '/')
 752                         pathp = kbasename(pathp);
 753                 rc = it(node, pathp, data);
 754                 if (rc)
 755                         return rc;
 756         }
 757         return 0;
 758 }
 759
 760 /**
 761  * of_get_flat_dt_subnode_by_name - get the subnode by given name
 762  *
 763  * @node: the parent node
 764  * @uname: the name of subnode
 765  * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
 766  */
 767
 768 int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
 769 {
 770         return fdt_subnode_offset(initial_boot_params, node, uname);
 771 }
 772
 773 /**
 774  * of_get_flat_dt_root - find the root node in the flat blob
 775  */
 776 unsigned long __init of_get_flat_dt_root(void)
 777 {
 778         return 0;
 779 }
 780
 781 /**
 782  * of_get_flat_dt_size - Return the total size of the FDT
 783  */
 784 int __init of_get_flat_dt_size(void)
 785 {
 786         return fdt_totalsize(initial_boot_params);
 787 }
 788
 789 /**
 790  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 791  *
 792  * This function can be used within scan_flattened_dt callback to get
 793  * access to properties
 794  */
 795 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 796                                        int *size)
 797 {
 798         return fdt_getprop(initial_boot_params, node, name, size);
 799 }
 800
 801 /**
 802  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 803  * @node: node to test
 804  * @compat: compatible string to compare with compatible list.
 805  */
 806 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 807 {
 808         return of_fdt_is_compatible(initial_boot_params, node, compat);
 809 }
 810
 811 /**
 812  * of_flat_dt_match - Return true if node matches a list of compatible values
 813  */
 814 int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 815 {
 816         return of_fdt_match(initial_boot_params, node, compat);
 817 }
 818
 819 /**
 820  * of_get_flat_dt_prop - Given a node in the flat blob, return the phandle
 821  */
 822 uint32_t __init of_get_flat_dt_phandle(unsigned long node)
 823 {
 824         return fdt_get_phandle(initial_boot_params, node);
 825 }
 826
 827 struct fdt_scan_status {
 828         const char *name;
 829         int namelen;
 830         int depth;
 831         int found;
 832         int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 833         void *data;
 834 };
 835
 836 const char * __init of_flat_dt_get_machine_name(void)
 837 {
 838         const char *name;
 839         unsigned long dt_root = of_get_flat_dt_root();
 840
 841         name = of_get_flat_dt_prop(dt_root, "model", NULL);
 842         if (!name)
 843                 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 844         return name;
 845 }
 846
 847 /**
 848  * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 849  *
 850  * @default_match: A machine specific ptr to return in case of no match.
 851  * @get_next_compat: callback function to return next compatible match table.
 852  *
 853  * Iterate through machine match tables to find the best match for the machine
 854  * compatible string in the FDT.
 855  */
 856 const void * __init of_flat_dt_match_machine(const void *default_match,
 857                 const void * (*get_next_compat)(const char * const**))
 858 {
 859         const void *data = NULL;
 860         const void *best_data = default_match;
 861         const char *const *compat;
 862         unsigned long dt_root;
 863         unsigned int best_score = ~1, score = 0;
 864
 865         dt_root = of_get_flat_dt_root();
 866         while ((data = get_next_compat(&compat))) {
 867                 score = of_flat_dt_match(dt_root, compat);
 868                 if (score > 0 && score < best_score) {
 869                         best_data = data;
 870                         best_score = score;
 871                 }
 872         }
 873         if (!best_data) {
 874                 const char *prop;
 875                 int size;
 876
 877                 pr_err("\n unrecognized device tree list:\n[ ");
 878
 879                 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 880                 if (prop) {
 881                         while (size > 0) {
 882                                 printk("'%s' ", prop);
 883                                 size -= strlen(prop) + 1;
 884                                 prop += strlen(prop) + 1;
 885                         }
 886                 }
 887                 printk("]\n\n");
 888                 return NULL;
 889         }
 890
 891         pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 892
 893         return best_data;
 894 }
 895
 896 #ifdef CONFIG_BLK_DEV_INITRD
 897 #ifndef __early_init_dt_declare_initrd
 898 static void __early_init_dt_declare_initrd(unsigned long start,
 899                                            unsigned long end)
 900 {
 901         initrd_start = (unsigned long)__va(start);
 902         initrd_end = (unsigned long)__va(end);
 903         initrd_below_start_ok = 1;
 904 }
 905 #endif
 906
 907 /**
 908  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 909  * @node: reference to node containing initrd location ('chosen')
 910  */
 911 static void __init early_init_dt_check_for_initrd(unsigned long node)
 912 {
 913         u64 start, end;
 914         int len;
 915         const __be32 *prop;
 916
 917         pr_debug("Looking for initrd properties... ");
 918
 919         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 920         if (!prop)
 921                 return;
 922         start = of_read_number(prop, len/4);
 923
 924         prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 925         if (!prop)
 926                 return;
 927         end = of_read_number(prop, len/4);
 928
 929         __early_init_dt_declare_initrd(start, end);
 930
 931         pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 932                  (unsigned long long)start, (unsigned long long)end);
 933 }
 934 #else
 935 static inline void early_init_dt_check_for_initrd(unsigned long node)
 936 {
 937 }
 938 #endif /* CONFIG_BLK_DEV_INITRD */
 939
 940 #ifdef CONFIG_SERIAL_EARLYCON
 941
 942 int __init early_init_dt_scan_chosen_stdout(void)
 943 {
 944         int offset;
 945         const char *p, *q, *options = NULL;
 946         int l;
 947         const struct earlycon_id *match;
 948         const void *fdt = initial_boot_params;
 949
 950         offset = fdt_path_offset(fdt, "/chosen");
 951         if (offset < 0)
 952                 offset = fdt_path_offset(fdt, "/chosen@0");
 953         if (offset < 0)
 954                 return -ENOENT;
 955
 956         p = fdt_getprop(fdt, offset, "stdout-path", &l);
 957         if (!p)
 958                 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 959         if (!p || !l)
 960                 return -ENOENT;
 961
 962         q = strchrnul(p, ':');
 963         if (*q != '\0')
 964                 options = q + 1;
 965         l = q - p;
 966
 967         /* Get the node specified by stdout-path */
 968         offset = fdt_path_offset_namelen(fdt, p, l);
 969         if (offset < 0) {
 970                 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
 971                 return 0;
 972         }
 973
 974         for (match = __earlycon_table; match < __earlycon_table_end; match++) {
 975                 if (!match->compatible[0])
 976                         continue;
 977
 978                 if (fdt_node_check_compatible(fdt, offset, match->compatible))
 979                         continue;
 980
 981                 of_setup_earlycon(match, offset, options);
 982                 return 0;
 983         }
 984         return -ENODEV;
 985 }
 986 #endif
 987
 988 /**
 989  * early_init_dt_scan_root - fetch the top level address and size cells
 990  */
 991 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 992                                    int depth, void *data)
 993 {
 994         const __be32 *prop;
 995
 996         if (depth != 0)
 997                 return 0;
 998
 999         dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
1000         dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
1001
1002         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
1003         if (prop)
1004                 dt_root_size_cells = be32_to_cpup(prop);
1005         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
1006
1007         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
1008         if (prop)
1009                 dt_root_addr_cells = be32_to_cpup(prop);
1010         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
1011
1012         /* break now */
1013         return 1;
1014 }
1015
1016 u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
1017 {
1018         const __be32 *p = *cellp;
1019
1020         *cellp = p + s;
1021         return of_read_number(p, s);
1022 }
1023
1024 /**
1025  * early_init_dt_scan_memory - Look for and parse memory nodes
1026  */
1027 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
1028                                      int depth, void *data)
1029 {
1030         const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
1031         const __be32 *reg, *endp;
1032         int l;
1033         bool hotpluggable;
1034
1035         /* We are scanning "memory" nodes only */
1036         if (type == NULL) {
1037                 /*
1038                  * The longtrail doesn't have a device_type on the
1039                  * /memory node, so look for the node called /memory@0.
1040                  */
1041                 if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0)
1042                         return 0;
1043         } else if (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 #ifdef CONFIG_HAVE_MEMBLOCK
1125 #ifndef MIN_MEMBLOCK_ADDR
1126 #define MIN_MEMBLOCK_ADDR       __pa(PAGE_OFFSET)
1127 #endif
1128 #ifndef MAX_MEMBLOCK_ADDR
1129 #define MAX_MEMBLOCK_ADDR       ((phys_addr_t)~0)
1130 #endif
1131
1132 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1133 {
1134         const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1135
1136         if (!PAGE_ALIGNED(base)) {
1137                 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1138                         pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1139                                 base, base + size);
1140                         return;
1141                 }
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 /*
1187  * called from unflatten_device_tree() to bootstrap devicetree itself
1188  * Architectures can override this definition if memblock isn't used
1189  */
1190 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
1191 {
1192         return __va(memblock_alloc(size, align));
1193 }
1194 #else
1195 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1196 {
1197         WARN_ON(1);
1198 }
1199
1200 int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1201 {
1202         return -ENOSYS;
1203 }
1204
1205 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1206                                         phys_addr_t size, bool nomap)
1207 {
1208         pr_err("Reserved memory not supported, ignoring range %pa - %pa%s\n",
1209                   &base, &size, nomap ? " (nomap)" : "");
1210         return -ENOSYS;
1211 }
1212
1213 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
1214 {
1215         WARN_ON(1);
1216         return NULL;
1217 }
1218 #endif
1219
1220 bool __init early_init_dt_verify(void *params)
1221 {
1222         if (!params)
1223                 return false;
1224
1225         /* check device tree validity */
1226         if (fdt_check_header(params))
1227                 return false;
1228
1229         /* Setup flat device-tree pointer */
1230         initial_boot_params = params;
1231         of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1232                                 fdt_totalsize(initial_boot_params));
1233         return true;
1234 }
1235
1236
1237 void __init early_init_dt_scan_nodes(void)
1238 {
1239         /* Retrieve various information from the /chosen node */
1240         of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1241
1242         /* Initialize {size,address}-cells info */
1243         of_scan_flat_dt(early_init_dt_scan_root, NULL);
1244
1245         /* Setup memory, calling early_init_dt_add_memory_arch */
1246         of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1247 }
1248
1249 bool __init early_init_dt_scan(void *params)
1250 {
1251         bool status;
1252
1253         status = early_init_dt_verify(params);
1254         if (!status)
1255                 return false;
1256
1257         early_init_dt_scan_nodes();
1258         return true;
1259 }
1260
1261 /**
1262  * unflatten_device_tree - create tree of device_nodes from flat blob
1263  *
1264  * unflattens the device-tree passed by the firmware, creating the
1265  * tree of struct device_node. It also fills the "name" and "type"
1266  * pointers of the nodes so the normal device-tree walking functions
1267  * can be used.
1268  */
1269 void __init unflatten_device_tree(void)
1270 {
1271         __unflatten_device_tree(initial_boot_params, NULL, &of_root,
1272                                 early_init_dt_alloc_memory_arch, false);
1273
1274         /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1275         of_alias_scan(early_init_dt_alloc_memory_arch);
1276
1277         unittest_unflatten_overlay_base();
1278 }
1279
1280 /**
1281  * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1282  *
1283  * Copies and unflattens the device-tree passed by the firmware, creating the
1284  * tree of struct device_node. It also fills the "name" and "type"
1285  * pointers of the nodes so the normal device-tree walking functions
1286  * can be used. This should only be used when the FDT memory has not been
1287  * reserved such is the case when the FDT is built-in to the kernel init
1288  * section. If the FDT memory is reserved already then unflatten_device_tree
1289  * should be used instead.
1290  */
1291 void __init unflatten_and_copy_device_tree(void)
1292 {
1293         int size;
1294         void *dt;
1295
1296         if (!initial_boot_params) {
1297                 pr_warn("No valid device tree found, continuing without\n");
1298                 return;
1299         }
1300
1301         size = fdt_totalsize(initial_boot_params);
1302         dt = early_init_dt_alloc_memory_arch(size,
1303                                              roundup_pow_of_two(FDT_V17_SIZE));
1304
1305         if (dt) {
1306                 memcpy(dt, initial_boot_params, size);
1307                 initial_boot_params = dt;
1308         }
1309         unflatten_device_tree();
1310 }
1311
1312 #ifdef CONFIG_SYSFS
1313 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1314                                struct bin_attribute *bin_attr,
1315                                char *buf, loff_t off, size_t count)
1316 {
1317         memcpy(buf, initial_boot_params + off, count);
1318         return count;
1319 }
1320
1321 static int __init of_fdt_raw_init(void)
1322 {
1323         static struct bin_attribute of_fdt_raw_attr =
1324                 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1325
1326         if (!initial_boot_params)
1327                 return 0;
1328
1329         if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1330                                      fdt_totalsize(initial_boot_params))) {
1331                 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1332                 return 0;
1333         }
1334         of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1335         return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1336 }
1337 late_initcall(of_fdt_raw_init);
1338 #endif
1339
1340 #endif /* CONFIG_OF_EARLY_FLATTREE */