linux/drivers/of/fdt.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Functions for working with the Flattened Device Tree data format
   4 *
   5 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
   6 * benh@kernel.crashing.org
   7 */
   8
   9#define pr_fmt(fmt)     "OF: fdt: " fmt
  10
  11#include <linux/crc32.h>
  12#include <linux/kernel.h>
  13#include <linux/initrd.h>
  14#include <linux/memblock.h>
  15#include <linux/mutex.h>
  16#include <linux/of.h>
  17#include <linux/of_fdt.h>
  18#include <linux/of_reserved_mem.h>
  19#include <linux/sizes.h>
  20#include <linux/string.h>
  21#include <linux/errno.h>
  22#include <linux/slab.h>
  23#include <linux/libfdt.h>
  24#include <linux/debugfs.h>
  25#include <linux/serial_core.h>
  26#include <linux/sysfs.h>
  27#include <linux/random.h>
  28
  29#include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  30#include <asm/page.h>
  31
  32#include "of_private.h"
  33
  34/*
  35 * of_fdt_limit_memory - limit the number of regions in the /memory node
  36 * @limit: maximum entries
  37 *
  38 * Adjust the flattened device tree to have at most 'limit' number of
  39 * memory entries in the /memory node. This function may be called
  40 * any time after initial_boot_param is set.
  41 */
  42void __init of_fdt_limit_memory(int limit)
  43{
  44        int memory;
  45        int len;
  46        const void *val;
  47        int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
  48        int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
  49        const __be32 *addr_prop;
  50        const __be32 *size_prop;
  51        int root_offset;
  52        int cell_size;
  53
  54        root_offset = fdt_path_offset(initial_boot_params, "/");
  55        if (root_offset < 0)
  56                return;
  57
  58        addr_prop = fdt_getprop(initial_boot_params, root_offset,
  59                                "#address-cells", NULL);
  60        if (addr_prop)
  61                nr_address_cells = fdt32_to_cpu(*addr_prop);
  62
  63        size_prop = fdt_getprop(initial_boot_params, root_offset,
  64                                "#size-cells", NULL);
  65        if (size_prop)
  66                nr_size_cells = fdt32_to_cpu(*size_prop);
  67
  68        cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
  69
  70        memory = fdt_path_offset(initial_boot_params, "/memory");
  71        if (memory > 0) {
  72                val = fdt_getprop(initial_boot_params, memory, "reg", &len);
  73                if (len > limit*cell_size) {
  74                        len = limit*cell_size;
  75                        pr_debug("Limiting number of entries to %d\n", limit);
  76                        fdt_setprop(initial_boot_params, memory, "reg", val,
  77                                        len);
  78                }
  79        }
  80}
  81
  82static bool of_fdt_device_is_available(const void *blob, unsigned long node)
  83{
  84        const char *status = fdt_getprop(blob, node, "status", NULL);
  85
  86        if (!status)
  87                return true;
  88
  89        if (!strcmp(status, "ok") || !strcmp(status, "okay"))
  90                return true;
  91
  92        return false;
  93}
  94
  95static void *unflatten_dt_alloc(void **mem, unsigned long size,
  96                                       unsigned long align)
  97{
  98        void *res;
  99
 100        *mem = PTR_ALIGN(*mem, align);
 101        res = *mem;
 102        *mem += size;
 103
 104        return res;
 105}
 106
 107static void populate_properties(const void *blob,
 108                                int offset,
 109                                void **mem,
 110                                struct device_node *np,
 111                                const char *nodename,
 112                                bool dryrun)
 113{
 114        struct property *pp, **pprev = NULL;
 115        int cur;
 116        bool has_name = false;
 117
 118        pprev = &np->properties;
 119        for (cur = fdt_first_property_offset(blob, offset);
 120             cur >= 0;
 121             cur = fdt_next_property_offset(blob, cur)) {
 122                const __be32 *val;
 123                const char *pname;
 124                u32 sz;
 125
 126                val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
 127                if (!val) {
 128                        pr_warn("Cannot locate property at 0x%x\n", cur);
 129                        continue;
 130                }
 131
 132                if (!pname) {
 133                        pr_warn("Cannot find property name at 0x%x\n", cur);
 134                        continue;
 135                }
 136
 137                if (!strcmp(pname, "name"))
 138                        has_name = true;
 139
 140                pp = unflatten_dt_alloc(mem, sizeof(struct property),
 141                                        __alignof__(struct property));
 142                if (dryrun)
 143                        continue;
 144
 145                /* We accept flattened tree phandles either in
 146                 * ePAPR-style "phandle" properties, or the
 147                 * legacy "linux,phandle" properties.  If both
 148                 * appear and have different values, things
 149                 * will get weird. Don't do that.
 150                 */
 151                if (!strcmp(pname, "phandle") ||
 152                    !strcmp(pname, "linux,phandle")) {
 153                        if (!np->phandle)
 154                                np->phandle = be32_to_cpup(val);
 155                }
 156
 157                /* And we process the "ibm,phandle" property
 158                 * used in pSeries dynamic device tree
 159                 * stuff
 160                 */
 161                if (!strcmp(pname, "ibm,phandle"))
 162                        np->phandle = be32_to_cpup(val);
 163
 164                pp->name   = (char *)pname;
 165                pp->length = sz;
 166                pp->value  = (__be32 *)val;
 167                *pprev     = pp;
 168                pprev      = &pp->next;
 169        }
 170
 171        /* With version 0x10 we may not have the name property,
 172         * recreate it here from the unit name if absent
 173         */
 174        if (!has_name) {
 175                const char *p = nodename, *ps = p, *pa = NULL;
 176                int len;
 177
 178                while (*p) {
 179                        if ((*p) == '@')
 180                                pa = p;
 181                        else if ((*p) == '/')
 182                                ps = p + 1;
 183                        p++;
 184                }
 185
 186                if (pa < ps)
 187                        pa = p;
 188                len = (pa - ps) + 1;
 189                pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
 190                                        __alignof__(struct property));
 191                if (!dryrun) {
 192                        pp->name   = "name";
 193                        pp->length = len;
 194                        pp->value  = pp + 1;
 195                        *pprev     = pp;
 196                        pprev      = &pp->next;
 197                        memcpy(pp->value, ps, len - 1);
 198                        ((char *)pp->value)[len - 1] = 0;
 199                        pr_debug("fixed up name for %s -> %s\n",
 200                                 nodename, (char *)pp->value);
 201                }
 202        }
 203
 204        if (!dryrun)
 205                *pprev = NULL;
 206}
 207
 208static bool populate_node(const void *blob,
 209                          int offset,
 210                          void **mem,
 211                          struct device_node *dad,
 212                          struct device_node **pnp,
 213                          bool dryrun)
 214{
 215        struct device_node *np;
 216        const char *pathp;
 217        unsigned int l, allocl;
 218
 219        pathp = fdt_get_name(blob, offset, &l);
 220        if (!pathp) {
 221                *pnp = NULL;
 222                return false;
 223        }
 224
 225        allocl = ++l;
 226
 227        np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
 228                                __alignof__(struct device_node));
 229        if (!dryrun) {
 230                char *fn;
 231                of_node_init(np);
 232                np->full_name = fn = ((char *)np) + sizeof(*np);
 233
 234                memcpy(fn, pathp, l);
 235
 236                if (dad != NULL) {
 237                        np->parent = dad;
 238                        np->sibling = dad->child;
 239                        dad->child = np;
 240                }
 241        }
 242
 243        populate_properties(blob, offset, mem, np, pathp, dryrun);
 244        if (!dryrun) {
 245                np->name = of_get_property(np, "name", NULL);
 246                if (!np->name)
 247                        np->name = "<NULL>";
 248        }
 249
 250        *pnp = np;
 251        return true;
 252}
 253
 254static void reverse_nodes(struct device_node *parent)
 255{
 256        struct device_node *child, *next;
 257
 258        /* In-depth first */
 259        child = parent->child;
 260        while (child) {
 261                reverse_nodes(child);
 262
 263                child = child->sibling;
 264        }
 265
 266        /* Reverse the nodes in the child list */
 267        child = parent->child;
 268        parent->child = NULL;
 269        while (child) {
 270                next = child->sibling;
 271
 272                child->sibling = parent->child;
 273                parent->child = child;
 274                child = next;
 275        }
 276}
 277
 278/**
 279 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
 280 * @blob: The parent device tree blob
 281 * @mem: Memory chunk to use for allocating device nodes and properties
 282 * @dad: Parent struct device_node
 283 * @nodepp: The device_node tree created by the call
 284 *
 285 * It returns the size of unflattened device tree or error code
 286 */
 287static int unflatten_dt_nodes(const void *blob,
 288                              void *mem,
 289                              struct device_node *dad,
 290                              struct device_node **nodepp)
 291{
 292        struct device_node *root;
 293        int offset = 0, depth = 0, initial_depth = 0;
 294#define FDT_MAX_DEPTH   64
 295        struct device_node *nps[FDT_MAX_DEPTH];
 296        void *base = mem;
 297        bool dryrun = !base;
 298
 299        if (nodepp)
 300                *nodepp = NULL;
 301
 302        /*
 303         * We're unflattening device sub-tree if @dad is valid. There are
 304         * possibly multiple nodes in the first level of depth. We need
 305         * set @depth to 1 to make fdt_next_node() happy as it bails
 306         * immediately when negative @depth is found. Otherwise, the device
 307         * nodes except the first one won't be unflattened successfully.
 308         */
 309        if (dad)
 310                depth = initial_depth = 1;
 311
 312        root = dad;
 313        nps[depth] = dad;
 314
 315        for (offset = 0;
 316             offset >= 0 && depth >= initial_depth;
 317             offset = fdt_next_node(blob, offset, &depth)) {
 318                if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
 319                        continue;
 320
 321                if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
 322                    !of_fdt_device_is_available(blob, offset))
 323                        continue;
 324
 325                if (!populate_node(blob, offset, &mem, nps[depth],
 326                                   &nps[depth+1], dryrun))
 327                        return mem - base;
 328
 329                if (!dryrun && nodepp && !*nodepp)
 330                        *nodepp = nps[depth+1];
 331                if (!dryrun && !root)
 332                        root = nps[depth+1];
 333        }
 334
 335        if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 336                pr_err("Error %d processing FDT\n", offset);
 337                return -EINVAL;
 338        }
 339
 340        /*
 341         * Reverse the child list. Some drivers assumes node order matches .dts
 342         * node order
 343         */
 344        if (!dryrun)
 345                reverse_nodes(root);
 346
 347        return mem - base;
 348}
 349
 350/**
 351 * __unflatten_device_tree - create tree of device_nodes from flat blob
 352 *
 353 * unflattens a device-tree, creating the
 354 * tree of struct device_node. It also fills the "name" and "type"
 355 * pointers of the nodes so the normal device-tree walking functions
 356 * can be used.
 357 * @blob: The blob to expand
 358 * @dad: Parent device node
 359 * @mynodes: The device_node tree created by the call
 360 * @dt_alloc: An allocator that provides a virtual address to memory
 361 * for the resulting tree
 362 * @detached: if true set OF_DETACHED on @mynodes
 363 *
 364 * Returns NULL on failure or the memory chunk containing the unflattened
 365 * device tree on success.
 366 */
 367void *__unflatten_device_tree(const void *blob,
 368                              struct device_node *dad,
 369                              struct device_node **mynodes,
 370                              void *(*dt_alloc)(u64 size, u64 align),
 371                              bool detached)
 372{
 373        int size;
 374        void *mem;
 375
 376        pr_debug(" -> unflatten_device_tree()\n");
 377
 378        if (!blob) {
 379                pr_debug("No device tree pointer\n");
 380                return NULL;
 381        }
 382
 383        pr_debug("Unflattening device tree:\n");
 384        pr_debug("magic: %08x\n", fdt_magic(blob));
 385        pr_debug("size: %08x\n", fdt_totalsize(blob));
 386        pr_debug("version: %08x\n", fdt_version(blob));
 387
 388        if (fdt_check_header(blob)) {
 389                pr_err("Invalid device tree blob header\n");
 390                return NULL;
 391        }
 392
 393        /* First pass, scan for size */
 394        size = unflatten_dt_nodes(blob, NULL, dad, NULL);
 395        if (size < 0)
 396                return NULL;
 397
 398        size = ALIGN(size, 4);
 399        pr_debug("  size is %d, allocating...\n", size);
 400
 401        /* Allocate memory for the expanded device tree */
 402        mem = dt_alloc(size + 4, __alignof__(struct device_node));
 403        if (!mem)
 404                return NULL;
 405
 406        memset(mem, 0, size);
 407
 408        *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 409
 410        pr_debug("  unflattening %p...\n", mem);
 411
 412        /* Second pass, do actual unflattening */
 413        unflatten_dt_nodes(blob, mem, dad, mynodes);
 414        if (be32_to_cpup(mem + size) != 0xdeadbeef)
 415                pr_warning("End of tree marker overwritten: %08x\n",
 416                           be32_to_cpup(mem + size));
 417
 418        if (detached && mynodes) {
 419                of_node_set_flag(*mynodes, OF_DETACHED);
 420                pr_debug("unflattened tree is detached\n");
 421        }
 422
 423        pr_debug(" <- unflatten_device_tree()\n");
 424        return mem;
 425}
 426
 427static void *kernel_tree_alloc(u64 size, u64 align)
 428{
 429        return kzalloc(size, GFP_KERNEL);
 430}
 431
 432static DEFINE_MUTEX(of_fdt_unflatten_mutex);
 433
 434/**
 435 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 436 * @blob: Flat device tree blob
 437 * @dad: Parent device node
 438 * @mynodes: The device tree created by the call
 439 *
 440 * unflattens the device-tree passed by the firmware, creating the
 441 * tree of struct device_node. It also fills the "name" and "type"
 442 * pointers of the nodes so the normal device-tree walking functions
 443 * can be used.
 444 *
 445 * Returns NULL on failure or the memory chunk containing the unflattened
 446 * device tree on success.
 447 */
 448void *of_fdt_unflatten_tree(const unsigned long *blob,
 449                            struct device_node *dad,
 450                            struct device_node **mynodes)
 451{
 452        void *mem;
 453
 454        mutex_lock(&of_fdt_unflatten_mutex);
 455        mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
 456                                      true);
 457        mutex_unlock(&of_fdt_unflatten_mutex);
 458
 459        return mem;
 460}
 461EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 462
 463/* Everything below here references initial_boot_params directly. */
 464int __initdata dt_root_addr_cells;
 465int __initdata dt_root_size_cells;
 466
 467void *initial_boot_params __ro_after_init;
 468
 469#ifdef CONFIG_OF_EARLY_FLATTREE
 470
 471static u32 of_fdt_crc32;
 472
 473/**
 474 * res_mem_reserve_reg() - reserve all memory described in 'reg' property
 475 */
 476static int __init __reserved_mem_reserve_reg(unsigned long node,
 477                                             const char *uname)
 478{
 479        int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 480        phys_addr_t base, size;
 481        int len;
 482        const __be32 *prop;
 483        int first = 1;
 484        bool nomap;
 485
 486        prop = of_get_flat_dt_prop(node, "reg", &len);
 487        if (!prop)
 488                return -ENOENT;
 489
 490        if (len && len % t_len != 0) {
 491                pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 492                       uname);
 493                return -EINVAL;
 494        }
 495
 496        nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 497
 498        while (len >= t_len) {
 499                base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 500                size = dt_mem_next_cell(dt_root_size_cells, &prop);
 501
 502                if (size &&
 503                    early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 504                        pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 505                                uname, &base, (unsigned long)size / SZ_1M);
 506                else
 507                        pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 508                                uname, &base, (unsigned long)size / SZ_1M);
 509
 510                len -= t_len;
 511                if (first) {
 512                        fdt_reserved_mem_save_node(node, uname, base, size);
 513                        first = 0;
 514                }
 515        }
 516        return 0;
 517}
 518
 519/**
 520 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 521 * in /reserved-memory matches the values supported by the current implementation,
 522 * also check if ranges property has been provided
 523 */
 524static int __init __reserved_mem_check_root(unsigned long node)
 525{
 526        const __be32 *prop;
 527
 528        prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 529        if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 530                return -EINVAL;
 531
 532        prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 533        if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 534                return -EINVAL;
 535
 536        prop = of_get_flat_dt_prop(node, "ranges", NULL);
 537        if (!prop)
 538                return -EINVAL;
 539        return 0;
 540}
 541
 542/**
 543 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 544 */
 545static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 546                                          int depth, void *data)
 547{
 548        static int found;
 549        int err;
 550
 551        if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 552                if (__reserved_mem_check_root(node) != 0) {
 553                        pr_err("Reserved memory: unsupported node format, ignoring\n");
 554                        /* break scan */
 555                        return 1;
 556                }
 557                found = 1;
 558                /* scan next node */
 559                return 0;
 560        } else if (!found) {
 561                /* scan next node */
 562                return 0;
 563        } else if (found && depth < 2) {
 564                /* scanning of /reserved-memory has been finished */
 565                return 1;
 566        }
 567
 568        if (!of_fdt_device_is_available(initial_boot_params, node))
 569                return 0;
 570
 571        err = __reserved_mem_reserve_reg(node, uname);
 572        if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 573                fdt_reserved_mem_save_node(node, uname, 0, 0);
 574
 575        /* scan next node */
 576        return 0;
 577}
 578
 579/**
 580 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 581 *
 582 * This function grabs memory from early allocator for device exclusive use
 583 * defined in device tree structures. It should be called by arch specific code
 584 * once the early allocator (i.e. memblock) has been fully activated.
 585 */
 586void __init early_init_fdt_scan_reserved_mem(void)
 587{
 588        int n;
 589        u64 base, size;
 590
 591        if (!initial_boot_params)
 592                return;
 593
 594        /* Process header /memreserve/ fields */
 595        for (n = 0; ; n++) {
 596                fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 597                if (!size)
 598                        break;
 599                early_init_dt_reserve_memory_arch(base, size, false);
 600        }
 601
 602        of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 603        fdt_init_reserved_mem();
 604}
 605
 606/**
 607 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
 608 */
 609void __init early_init_fdt_reserve_self(void)
 610{
 611        if (!initial_boot_params)
 612                return;
 613
 614        /* Reserve the dtb region */
 615        early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
 616                                          fdt_totalsize(initial_boot_params),
 617                                          false);
 618}
 619
 620/**
 621 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 622 * @it: callback function
 623 * @data: context data pointer
 624 *
 625 * This function is used to scan the flattened device-tree, it is
 626 * used to extract the memory information at boot before we can
 627 * unflatten the tree
 628 */
 629int __init of_scan_flat_dt(int (*it)(unsigned long node,
 630                                     const char *uname, int depth,
 631                                     void *data),
 632                           void *data)
 633{
 634        const void *blob = initial_boot_params;
 635        const char *pathp;
 636        int offset, rc = 0, depth = -1;
 637
 638        if (!blob)
 639                return 0;
 640
 641        for (offset = fdt_next_node(blob, -1, &depth);
 642             offset >= 0 && depth >= 0 && !rc;
 643             offset = fdt_next_node(blob, offset, &depth)) {
 644
 645                pathp = fdt_get_name(blob, offset, NULL);
 646                if (*pathp == '/')
 647                        pathp = kbasename(pathp);
 648                rc = it(offset, pathp, depth, data);
 649        }
 650        return rc;
 651}
 652
 653/**
 654 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
 655 * @it: callback function
 656 * @data: context data pointer
 657 *
 658 * This function is used to scan sub-nodes of a node.
 659 */
 660int __init of_scan_flat_dt_subnodes(unsigned long parent,
 661                                    int (*it)(unsigned long node,
 662                                              const char *uname,
 663                                              void *data),
 664                                    void *data)
 665{
 666        const void *blob = initial_boot_params;
 667        int node;
 668
 669        fdt_for_each_subnode(node, blob, parent) {
 670                const char *pathp;
 671                int rc;
 672
 673                pathp = fdt_get_name(blob, node, NULL);
 674                if (*pathp == '/')
 675                        pathp = kbasename(pathp);
 676                rc = it(node, pathp, data);
 677                if (rc)
 678                        return rc;
 679        }
 680        return 0;
 681}
 682
 683/**
 684 * of_get_flat_dt_subnode_by_name - get the subnode by given name
 685 *
 686 * @node: the parent node
 687 * @uname: the name of subnode
 688 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
 689 */
 690
 691int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
 692{
 693        return fdt_subnode_offset(initial_boot_params, node, uname);
 694}
 695
 696/**
 697 * of_get_flat_dt_root - find the root node in the flat blob
 698 */
 699unsigned long __init of_get_flat_dt_root(void)
 700{
 701        return 0;
 702}
 703
 704/**
 705 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 706 *
 707 * This function can be used within scan_flattened_dt callback to get
 708 * access to properties
 709 */
 710const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 711                                       int *size)
 712{
 713        return fdt_getprop(initial_boot_params, node, name, size);
 714}
 715
 716/**
 717 * of_fdt_is_compatible - Return true if given node from the given blob has
 718 * compat in its compatible list
 719 * @blob: A device tree blob
 720 * @node: node to test
 721 * @compat: compatible string to compare with compatible list.
 722 *
 723 * On match, returns a non-zero value with smaller values returned for more
 724 * specific compatible values.
 725 */
 726static int of_fdt_is_compatible(const void *blob,
 727                      unsigned long node, const char *compat)
 728{
 729        const char *cp;
 730        int cplen;
 731        unsigned long l, score = 0;
 732
 733        cp = fdt_getprop(blob, node, "compatible", &cplen);
 734        if (cp == NULL)
 735                return 0;
 736        while (cplen > 0) {
 737                score++;
 738                if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 739                        return score;
 740                l = strlen(cp) + 1;
 741                cp += l;
 742                cplen -= l;
 743        }
 744
 745        return 0;
 746}
 747
 748/**
 749 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 750 * @node: node to test
 751 * @compat: compatible string to compare with compatible list.
 752 */
 753int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 754{
 755        return of_fdt_is_compatible(initial_boot_params, node, compat);
 756}
 757
 758/**
 759 * of_flat_dt_match - Return true if node matches a list of compatible values
 760 */
 761static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 762{
 763        unsigned int tmp, score = 0;
 764
 765        if (!compat)
 766                return 0;
 767
 768        while (*compat) {
 769                tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
 770                if (tmp && (score == 0 || (tmp < score)))
 771                        score = tmp;
 772                compat++;
 773        }
 774
 775        return score;
 776}
 777
 778/**
 779 * of_get_flat_dt_prop - Given a node in the flat blob, return the phandle
 780 */
 781uint32_t __init of_get_flat_dt_phandle(unsigned long node)
 782{
 783        return fdt_get_phandle(initial_boot_params, node);
 784}
 785
 786struct fdt_scan_status {
 787        const char *name;
 788        int namelen;
 789        int depth;
 790        int found;
 791        int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 792        void *data;
 793};
 794
 795const char * __init of_flat_dt_get_machine_name(void)
 796{
 797        const char *name;
 798        unsigned long dt_root = of_get_flat_dt_root();
 799
 800        name = of_get_flat_dt_prop(dt_root, "model", NULL);
 801        if (!name)
 802                name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 803        return name;
 804}
 805
 806/**
 807 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 808 *
 809 * @default_match: A machine specific ptr to return in case of no match.
 810 * @get_next_compat: callback function to return next compatible match table.
 811 *
 812 * Iterate through machine match tables to find the best match for the machine
 813 * compatible string in the FDT.
 814 */
 815const void * __init of_flat_dt_match_machine(const void *default_match,
 816                const void * (*get_next_compat)(const char * const**))
 817{
 818        const void *data = NULL;
 819        const void *best_data = default_match;
 820        const char *const *compat;
 821        unsigned long dt_root;
 822        unsigned int best_score = ~1, score = 0;
 823
 824        dt_root = of_get_flat_dt_root();
 825        while ((data = get_next_compat(&compat))) {
 826                score = of_flat_dt_match(dt_root, compat);
 827                if (score > 0 && score < best_score) {
 828                        best_data = data;
 829                        best_score = score;
 830                }
 831        }
 832        if (!best_data) {
 833                const char *prop;
 834                int size;
 835
 836                pr_err("\n unrecognized device tree list:\n[ ");
 837
 838                prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 839                if (prop) {
 840                        while (size > 0) {
 841                                printk("'%s' ", prop);
 842                                size -= strlen(prop) + 1;
 843                                prop += strlen(prop) + 1;
 844                        }
 845                }
 846                printk("]\n\n");
 847                return NULL;
 848        }
 849
 850        pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 851
 852        return best_data;
 853}
 854
 855#ifdef CONFIG_BLK_DEV_INITRD
 856static void __early_init_dt_declare_initrd(unsigned long start,
 857                                           unsigned long end)
 858{
 859        /* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is
 860         * enabled since __va() is called too early. ARM64 does make use
 861         * of phys_initrd_start/phys_initrd_size so we can skip this
 862         * conversion.
 863         */
 864        if (!IS_ENABLED(CONFIG_ARM64)) {
 865                initrd_start = (unsigned long)__va(start);
 866                initrd_end = (unsigned long)__va(end);
 867                initrd_below_start_ok = 1;
 868        }
 869}
 870
 871/**
 872 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 873 * @node: reference to node containing initrd location ('chosen')
 874 */
 875static void __init early_init_dt_check_for_initrd(unsigned long node)
 876{
 877        u64 start, end;
 878        int len;
 879        const __be32 *prop;
 880
 881        pr_debug("Looking for initrd properties... ");
 882
 883        prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 884        if (!prop)
 885                return;
 886        start = of_read_number(prop, len/4);
 887
 888        prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 889        if (!prop)
 890                return;
 891        end = of_read_number(prop, len/4);
 892
 893        __early_init_dt_declare_initrd(start, end);
 894        phys_initrd_start = start;
 895        phys_initrd_size = end - start;
 896
 897        pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 898                 (unsigned long long)start, (unsigned long long)end);
 899}
 900#else
 901static inline void early_init_dt_check_for_initrd(unsigned long node)
 902{
 903}
 904#endif /* CONFIG_BLK_DEV_INITRD */
 905
 906#ifdef CONFIG_SERIAL_EARLYCON
 907
 908int __init early_init_dt_scan_chosen_stdout(void)
 909{
 910        int offset;
 911        const char *p, *q, *options = NULL;
 912        int l;
 913        const struct earlycon_id **p_match;
 914        const void *fdt = initial_boot_params;
 915
 916        offset = fdt_path_offset(fdt, "/chosen");
 917        if (offset < 0)
 918                offset = fdt_path_offset(fdt, "/chosen@0");
 919        if (offset < 0)
 920                return -ENOENT;
 921
 922        p = fdt_getprop(fdt, offset, "stdout-path", &l);
 923        if (!p)
 924                p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 925        if (!p || !l)
 926                return -ENOENT;
 927
 928        q = strchrnul(p, ':');
 929        if (*q != '\0')
 930                options = q + 1;
 931        l = q - p;
 932
 933        /* Get the node specified by stdout-path */
 934        offset = fdt_path_offset_namelen(fdt, p, l);
 935        if (offset < 0) {
 936                pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
 937                return 0;
 938        }
 939
 940        for (p_match = __earlycon_table; p_match < __earlycon_table_end;
 941             p_match++) {
 942                const struct earlycon_id *match = *p_match;
 943
 944                if (!match->compatible[0])
 945                        continue;
 946
 947                if (fdt_node_check_compatible(fdt, offset, match->compatible))
 948                        continue;
 949
 950                of_setup_earlycon(match, offset, options);
 951                return 0;
 952        }
 953        return -ENODEV;
 954}
 955#endif
 956
 957/**
 958 * early_init_dt_scan_root - fetch the top level address and size cells
 959 */
 960int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 961                                   int depth, void *data)
 962{
 963        const __be32 *prop;
 964
 965        if (depth != 0)
 966                return 0;
 967
 968        dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 969        dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 970
 971        prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 972        if (prop)
 973                dt_root_size_cells = be32_to_cpup(prop);
 974        pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 975
 976        prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 977        if (prop)
 978                dt_root_addr_cells = be32_to_cpup(prop);
 979        pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 980
 981        /* break now */
 982        return 1;
 983}
 984
 985u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
 986{
 987        const __be32 *p = *cellp;
 988
 989        *cellp = p + s;
 990        return of_read_number(p, s);
 991}
 992
 993/**
 994 * early_init_dt_scan_memory - Look for and parse memory nodes
 995 */
 996int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 997                                     int depth, void *data)
 998{
 999        const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
1000        const __be32 *reg, *endp;
1001        int l;
1002        bool hotpluggable;
1003
1004        /* We are scanning "memory" nodes only */
1005        if (type == NULL || strcmp(type, "memory") != 0)
1006                return 0;
1007
1008        reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1009        if (reg == NULL)
1010                reg = of_get_flat_dt_prop(node, "reg", &l);
1011        if (reg == NULL)
1012                return 0;
1013
1014        endp = reg + (l / sizeof(__be32));
1015        hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1016
1017        pr_debug("memory scan node %s, reg size %d,\n", uname, l);
1018
1019        while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1020                u64 base, size;
1021
1022                base = dt_mem_next_cell(dt_root_addr_cells, &reg);
1023                size = dt_mem_next_cell(dt_root_size_cells, &reg);
1024
1025                if (size == 0)
1026                        continue;
1027                pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
1028                    (unsigned long long)size);
1029
1030                early_init_dt_add_memory_arch(base, size);
1031
1032                if (!hotpluggable)
1033                        continue;
1034
1035                if (early_init_dt_mark_hotplug_memory_arch(base, size))
1036                        pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1037                                base, base + size);
1038        }
1039
1040        return 0;
1041}
1042
1043int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
1044                                     int depth, void *data)
1045{
1046        int l;
1047        const char *p;
1048        const void *rng_seed;
1049
1050        pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
1051
1052        if (depth != 1 || !data ||
1053            (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
1054                return 0;
1055
1056        early_init_dt_check_for_initrd(node);
1057
1058        /* Retrieve command line */
1059        p = of_get_flat_dt_prop(node, "bootargs", &l);
1060        if (p != NULL && l > 0)
1061                strlcpy(data, p, min(l, COMMAND_LINE_SIZE));
1062
1063        /*
1064         * CONFIG_CMDLINE is meant to be a default in case nothing else
1065         * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1066         * is set in which case we override whatever was found earlier.
1067         */
1068#ifdef CONFIG_CMDLINE
1069#if defined(CONFIG_CMDLINE_EXTEND)
1070        strlcat(data, " ", COMMAND_LINE_SIZE);
1071        strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1072#elif defined(CONFIG_CMDLINE_FORCE)
1073        strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1074#else
1075        /* No arguments from boot loader, use kernel's  cmdl*/
1076        if (!((char *)data)[0])
1077                strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1078#endif
1079#endif /* CONFIG_CMDLINE */
1080
1081        pr_debug("Command line is: %s\n", (char*)data);
1082
1083        rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1084        if (rng_seed && l > 0) {
1085                add_bootloader_randomness(rng_seed, l);
1086
1087                /* try to clear seed so it won't be found. */
1088                fdt_nop_property(initial_boot_params, node, "rng-seed");
1089
1090                /* update CRC check value */
1091                of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1092                                fdt_totalsize(initial_boot_params));
1093        }
1094
1095        /* break now */
1096        return 1;
1097}
1098
1099#ifndef MIN_MEMBLOCK_ADDR
1100#define MIN_MEMBLOCK_ADDR       __pa(PAGE_OFFSET)
1101#endif
1102#ifndef MAX_MEMBLOCK_ADDR
1103#define MAX_MEMBLOCK_ADDR       ((phys_addr_t)~0)
1104#endif
1105
1106void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1107{
1108        const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1109
1110        if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1111                pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1112                        base, base + size);
1113                return;
1114        }
1115
1116        if (!PAGE_ALIGNED(base)) {
1117                size -= PAGE_SIZE - (base & ~PAGE_MASK);
1118                base = PAGE_ALIGN(base);
1119        }
1120        size &= PAGE_MASK;
1121
1122        if (base > MAX_MEMBLOCK_ADDR) {
1123                pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1124                                base, base + size);
1125                return;
1126        }
1127
1128        if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1129                pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1130                                ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1131                size = MAX_MEMBLOCK_ADDR - base + 1;
1132        }
1133
1134        if (base + size < phys_offset) {
1135                pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1136                           base, base + size);
1137                return;
1138        }
1139        if (base < phys_offset) {
1140                pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1141                           base, phys_offset);
1142                size -= phys_offset - base;
1143                base = phys_offset;
1144        }
1145        memblock_add(base, size);
1146}
1147
1148int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1149{
1150        return memblock_mark_hotplug(base, size);
1151}
1152
1153int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1154                                        phys_addr_t size, bool nomap)
1155{
1156        if (nomap)
1157                return memblock_remove(base, size);
1158        return memblock_reserve(base, size);
1159}
1160
1161static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1162{
1163        void *ptr = memblock_alloc(size, align);
1164
1165        if (!ptr)
1166                panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1167                      __func__, size, align);
1168
1169        return ptr;
1170}
1171
1172bool __init early_init_dt_verify(void *params)
1173{
1174        if (!params)
1175                return false;
1176
1177        /* check device tree validity */
1178        if (fdt_check_header(params))
1179                return false;
1180
1181        /* Setup flat device-tree pointer */
1182        initial_boot_params = params;
1183        of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1184                                fdt_totalsize(initial_boot_params));
1185        return true;
1186}
1187
1188
1189void __init early_init_dt_scan_nodes(void)
1190{
1191        int rc = 0;
1192
1193        /* Retrieve various information from the /chosen node */
1194        rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1195        if (!rc)
1196                pr_warn("No chosen node found, continuing without\n");
1197
1198        /* Initialize {size,address}-cells info */
1199        of_scan_flat_dt(early_init_dt_scan_root, NULL);
1200
1201        /* Setup memory, calling early_init_dt_add_memory_arch */
1202        of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1203}
1204
1205bool __init early_init_dt_scan(void *params)
1206{
1207        bool status;
1208
1209        status = early_init_dt_verify(params);
1210        if (!status)
1211                return false;
1212
1213        early_init_dt_scan_nodes();
1214        return true;
1215}
1216
1217/**
1218 * unflatten_device_tree - create tree of device_nodes from flat blob
1219 *
1220 * unflattens the device-tree passed by the firmware, creating the
1221 * tree of struct device_node. It also fills the "name" and "type"
1222 * pointers of the nodes so the normal device-tree walking functions
1223 * can be used.
1224 */
1225void __init unflatten_device_tree(void)
1226{
1227        __unflatten_device_tree(initial_boot_params, NULL, &of_root,
1228                                early_init_dt_alloc_memory_arch, false);
1229
1230        /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1231        of_alias_scan(early_init_dt_alloc_memory_arch);
1232
1233        unittest_unflatten_overlay_base();
1234}
1235
1236/**
1237 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1238 *
1239 * Copies and 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. This should only be used when the FDT memory has not been
1243 * reserved such is the case when the FDT is built-in to the kernel init
1244 * section. If the FDT memory is reserved already then unflatten_device_tree
1245 * should be used instead.
1246 */
1247void __init unflatten_and_copy_device_tree(void)
1248{
1249        int size;
1250        void *dt;
1251
1252        if (!initial_boot_params) {
1253                pr_warn("No valid device tree found, continuing without\n");
1254                return;
1255        }
1256
1257        size = fdt_totalsize(initial_boot_params);
1258        dt = early_init_dt_alloc_memory_arch(size,
1259                                             roundup_pow_of_two(FDT_V17_SIZE));
1260
1261        if (dt) {
1262                memcpy(dt, initial_boot_params, size);
1263                initial_boot_params = dt;
1264        }
1265        unflatten_device_tree();
1266}
1267
1268#ifdef CONFIG_SYSFS
1269static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1270                               struct bin_attribute *bin_attr,
1271                               char *buf, loff_t off, size_t count)
1272{
1273        memcpy(buf, initial_boot_params + off, count);
1274        return count;
1275}
1276
1277static int __init of_fdt_raw_init(void)
1278{
1279        static struct bin_attribute of_fdt_raw_attr =
1280                __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1281
1282        if (!initial_boot_params)
1283                return 0;
1284
1285        if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1286                                     fdt_totalsize(initial_boot_params))) {
1287                pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1288                return 0;
1289        }
1290        of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1291        return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1292}
1293late_initcall(of_fdt_raw_init);
1294#endif
1295
1296#endif /* CONFIG_OF_EARLY_FLATTREE */
1297