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 #include <linux/kernel.h>
  13 #include <linux/initrd.h>
  14 #include <linux/memblock.h>
  15 #include <linux/of.h>
  16 #include <linux/of_fdt.h>
  17 #include <linux/of_reserved_mem.h>
  18 #include <linux/sizes.h>
  19 #include <linux/string.h>
  20 #include <linux/errno.h>
  21 #include <linux/slab.h>
  22 #include <linux/libfdt.h>
  23 #include <linux/debugfs.h>
  24 #include <linux/serial_core.h>
  25
  26 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  27 #include <asm/page.h>
  28
  29 /**
  30  * of_fdt_is_compatible - Return true if given node from the given blob has
  31  * compat in its compatible list
  32  * @blob: A device tree blob
  33  * @node: node to test
  34  * @compat: compatible string to compare with compatible list.
  35  *
  36  * On match, returns a non-zero value with smaller values returned for more
  37  * specific compatible values.
  38  */
  39 int of_fdt_is_compatible(const void *blob,
  40                       unsigned long node, const char *compat)
  41 {
  42         const char *cp;
  43         int cplen;
  44         unsigned long l, score = 0;
  45
  46         cp = fdt_getprop(blob, node, "compatible", &cplen);
  47         if (cp == NULL)
  48                 return 0;
  49         while (cplen > 0) {
  50                 score++;
  51                 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
  52                         return score;
  53                 l = strlen(cp) + 1;
  54                 cp += l;
  55                 cplen -= l;
  56         }
  57
  58         return 0;
  59 }
  60
  61 /**
  62  * of_fdt_match - Return true if node matches a list of compatible values
  63  */
  64 int of_fdt_match(const void *blob, unsigned long node,
  65                  const char *const *compat)
  66 {
  67         unsigned int tmp, score = 0;
  68
  69         if (!compat)
  70                 return 0;
  71
  72         while (*compat) {
  73                 tmp = of_fdt_is_compatible(blob, node, *compat);
  74                 if (tmp && (score == 0 || (tmp < score)))
  75                         score = tmp;
  76                 compat++;
  77         }
  78
  79         return score;
  80 }
  81
  82 static void *unflatten_dt_alloc(void **mem, unsigned long size,
  83                                        unsigned long align)
  84 {
  85         void *res;
  86
  87         *mem = PTR_ALIGN(*mem, align);
  88         res = *mem;
  89         *mem += size;
  90
  91         return res;
  92 }
  93
  94 /**
  95  * unflatten_dt_node - Alloc and populate a device_node from the flat tree
  96  * @blob: The parent device tree blob
  97  * @mem: Memory chunk to use for allocating device nodes and properties
  98  * @p: pointer to node in flat tree
  99  * @dad: Parent struct device_node
 100  * @allnextpp: pointer to ->allnext from last allocated device_node
 101  * @fpsize: Size of the node path up at the current depth.
 102  */
 103 static void * unflatten_dt_node(void *blob,
 104                                 void *mem,
 105                                 int *poffset,
 106                                 struct device_node *dad,
 107                                 struct device_node ***allnextpp,
 108                                 unsigned long fpsize)
 109 {
 110         const __be32 *p;
 111         struct device_node *np;
 112         struct property *pp, **prev_pp = NULL;
 113         const char *pathp;
 114         unsigned int l, allocl;
 115         static int depth = 0;
 116         int old_depth;
 117         int offset;
 118         int has_name = 0;
 119         int new_format = 0;
 120
 121         pathp = fdt_get_name(blob, *poffset, &l);
 122         if (!pathp)
 123                 return mem;
 124
 125         allocl = l++;
 126
 127         /* version 0x10 has a more compact unit name here instead of the full
 128          * path. we accumulate the full path size using "fpsize", we'll rebuild
 129          * it later. We detect this because the first character of the name is
 130          * not '/'.
 131          */
 132         if ((*pathp) != '/') {
 133                 new_format = 1;
 134                 if (fpsize == 0) {
 135                         /* root node: special case. fpsize accounts for path
 136                          * plus terminating zero. root node only has '/', so
 137                          * fpsize should be 2, but we want to avoid the first
 138                          * level nodes to have two '/' so we use fpsize 1 here
 139                          */
 140                         fpsize = 1;
 141                         allocl = 2;
 142                         l = 1;
 143                         pathp = "";
 144                 } else {
 145                         /* account for '/' and path size minus terminal 0
 146                          * already in 'l'
 147                          */
 148                         fpsize += l;
 149                         allocl = fpsize;
 150                 }
 151         }
 152
 153         np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
 154                                 __alignof__(struct device_node));
 155         if (allnextpp) {
 156                 char *fn;
 157                 of_node_init(np);
 158                 np->full_name = fn = ((char *)np) + sizeof(*np);
 159                 if (new_format) {
 160                         /* rebuild full path for new format */
 161                         if (dad && dad->parent) {
 162                                 strcpy(fn, dad->full_name);
 163 #ifdef DEBUG
 164                                 if ((strlen(fn) + l + 1) != allocl) {
 165                                         pr_debug("%s: p: %d, l: %d, a: %d\n",
 166                                                 pathp, (int)strlen(fn),
 167                                                 l, allocl);
 168                                 }
 169 #endif
 170                                 fn += strlen(fn);
 171                         }
 172                         *(fn++) = '/';
 173                 }
 174                 memcpy(fn, pathp, l);
 175
 176                 prev_pp = &np->properties;
 177                 **allnextpp = np;
 178                 *allnextpp = &np->allnext;
 179                 if (dad != NULL) {
 180                         np->parent = dad;
 181                         /* we temporarily use the next field as `last_child'*/
 182                         if (dad->next == NULL)
 183                                 dad->child = np;
 184                         else
 185                                 dad->next->sibling = np;
 186                         dad->next = np;
 187                 }
 188         }
 189         /* process properties */
 190         for (offset = fdt_first_property_offset(blob, *poffset);
 191              (offset >= 0);
 192              (offset = fdt_next_property_offset(blob, offset))) {
 193                 const char *pname;
 194                 u32 sz;
 195
 196                 if (!(p = fdt_getprop_by_offset(blob, offset, &pname, &sz))) {
 197                         offset = -FDT_ERR_INTERNAL;
 198                         break;
 199                 }
 200
 201                 if (pname == NULL) {
 202                         pr_info("Can't find property name in list !\n");
 203                         break;
 204                 }
 205                 if (strcmp(pname, "name") == 0)
 206                         has_name = 1;
 207                 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
 208                                         __alignof__(struct property));
 209                 if (allnextpp) {
 210                         /* We accept flattened tree phandles either in
 211                          * ePAPR-style "phandle" properties, or the
 212                          * legacy "linux,phandle" properties.  If both
 213                          * appear and have different values, things
 214                          * will get weird.  Don't do that. */
 215                         if ((strcmp(pname, "phandle") == 0) ||
 216                             (strcmp(pname, "linux,phandle") == 0)) {
 217                                 if (np->phandle == 0)
 218                                         np->phandle = be32_to_cpup(p);
 219                         }
 220                         /* And we process the "ibm,phandle" property
 221                          * used in pSeries dynamic device tree
 222                          * stuff */
 223                         if (strcmp(pname, "ibm,phandle") == 0)
 224                                 np->phandle = be32_to_cpup(p);
 225                         pp->name = (char *)pname;
 226                         pp->length = sz;
 227                         pp->value = (__be32 *)p;
 228                         *prev_pp = pp;
 229                         prev_pp = &pp->next;
 230                 }
 231         }
 232         /* with version 0x10 we may not have the name property, recreate
 233          * it here from the unit name if absent
 234          */
 235         if (!has_name) {
 236                 const char *p1 = pathp, *ps = pathp, *pa = NULL;
 237                 int sz;
 238
 239                 while (*p1) {
 240                         if ((*p1) == '@')
 241                                 pa = p1;
 242                         if ((*p1) == '/')
 243                                 ps = p1 + 1;
 244                         p1++;
 245                 }
 246                 if (pa < ps)
 247                         pa = p1;
 248                 sz = (pa - ps) + 1;
 249                 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
 250                                         __alignof__(struct property));
 251                 if (allnextpp) {
 252                         pp->name = "name";
 253                         pp->length = sz;
 254                         pp->value = pp + 1;
 255                         *prev_pp = pp;
 256                         prev_pp = &pp->next;
 257                         memcpy(pp->value, ps, sz - 1);
 258                         ((char *)pp->value)[sz - 1] = 0;
 259                         pr_debug("fixed up name for %s -> %s\n", pathp,
 260                                 (char *)pp->value);
 261                 }
 262         }
 263         if (allnextpp) {
 264                 *prev_pp = NULL;
 265                 np->name = of_get_property(np, "name", NULL);
 266                 np->type = of_get_property(np, "device_type", NULL);
 267
 268                 if (!np->name)
 269                         np->name = "<NULL>";
 270                 if (!np->type)
 271                         np->type = "<NULL>";
 272         }
 273
 274         old_depth = depth;
 275         *poffset = fdt_next_node(blob, *poffset, &depth);
 276         if (depth < 0)
 277                 depth = 0;
 278         while (*poffset > 0 && depth > old_depth)
 279                 mem = unflatten_dt_node(blob, mem, poffset, np, allnextpp,
 280                                         fpsize);
 281
 282         if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND)
 283                 pr_err("unflatten: error %d processing FDT\n", *poffset);
 284
 285         return mem;
 286 }
 287
 288 /**
 289  * __unflatten_device_tree - create tree of device_nodes from flat blob
 290  *
 291  * unflattens a device-tree, creating the
 292  * tree of struct device_node. It also fills the "name" and "type"
 293  * pointers of the nodes so the normal device-tree walking functions
 294  * can be used.
 295  * @blob: The blob to expand
 296  * @mynodes: The device_node tree created by the call
 297  * @dt_alloc: An allocator that provides a virtual address to memory
 298  * for the resulting tree
 299  */
 300 static void __unflatten_device_tree(void *blob,
 301                              struct device_node **mynodes,
 302                              void * (*dt_alloc)(u64 size, u64 align))
 303 {
 304         unsigned long size;
 305         int start;
 306         void *mem;
 307         struct device_node **allnextp = mynodes;
 308
 309         pr_debug(" -> unflatten_device_tree()\n");
 310
 311         if (!blob) {
 312                 pr_debug("No device tree pointer\n");
 313                 return;
 314         }
 315
 316         pr_debug("Unflattening device tree:\n");
 317         pr_debug("magic: %08x\n", fdt_magic(blob));
 318         pr_debug("size: %08x\n", fdt_totalsize(blob));
 319         pr_debug("version: %08x\n", fdt_version(blob));
 320
 321         if (fdt_check_header(blob)) {
 322                 pr_err("Invalid device tree blob header\n");
 323                 return;
 324         }
 325
 326         /* First pass, scan for size */
 327         start = 0;
 328         size = (unsigned long)unflatten_dt_node(blob, NULL, &start, NULL, NULL, 0);
 329         size = ALIGN(size, 4);
 330
 331         pr_debug("  size is %lx, allocating...\n", size);
 332
 333         /* Allocate memory for the expanded device tree */
 334         mem = dt_alloc(size + 4, __alignof__(struct device_node));
 335         memset(mem, 0, size);
 336
 337         *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 338
 339         pr_debug("  unflattening %p...\n", mem);
 340
 341         /* Second pass, do actual unflattening */
 342         start = 0;
 343         unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
 344         if (be32_to_cpup(mem + size) != 0xdeadbeef)
 345                 pr_warning("End of tree marker overwritten: %08x\n",
 346                            be32_to_cpup(mem + size));
 347         *allnextp = NULL;
 348
 349         pr_debug(" <- unflatten_device_tree()\n");
 350 }
 351
 352 static void *kernel_tree_alloc(u64 size, u64 align)
 353 {
 354         return kzalloc(size, GFP_KERNEL);
 355 }
 356
 357 /**
 358  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 359  *
 360  * unflattens the device-tree passed by the firmware, creating the
 361  * tree of struct device_node. It also fills the "name" and "type"
 362  * pointers of the nodes so the normal device-tree walking functions
 363  * can be used.
 364  */
 365 void of_fdt_unflatten_tree(unsigned long *blob,
 366                         struct device_node **mynodes)
 367 {
 368         __unflatten_device_tree(blob, mynodes, &kernel_tree_alloc);
 369 }
 370 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 371
 372 /* Everything below here references initial_boot_params directly. */
 373 int __initdata dt_root_addr_cells;
 374 int __initdata dt_root_size_cells;
 375
 376 void *initial_boot_params;
 377
 378 #ifdef CONFIG_OF_EARLY_FLATTREE
 379
 380 /**
 381  * res_mem_reserve_reg() - reserve all memory described in 'reg' property
 382  */
 383 static int __init __reserved_mem_reserve_reg(unsigned long node,
 384                                              const char *uname)
 385 {
 386         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 387         phys_addr_t base, size;
 388         int len;
 389         const __be32 *prop;
 390         int nomap, first = 1;
 391
 392         prop = of_get_flat_dt_prop(node, "reg", &len);
 393         if (!prop)
 394                 return -ENOENT;
 395
 396         if (len && len % t_len != 0) {
 397                 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 398                        uname);
 399                 return -EINVAL;
 400         }
 401
 402         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 403
 404         while (len >= t_len) {
 405                 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 406                 size = dt_mem_next_cell(dt_root_size_cells, &prop);
 407
 408                 if (base && size &&
 409                     early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 410                         pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 411                                 uname, &base, (unsigned long)size / SZ_1M);
 412                 else
 413                         pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 414                                 uname, &base, (unsigned long)size / SZ_1M);
 415
 416                 len -= t_len;
 417                 if (first) {
 418                         fdt_reserved_mem_save_node(node, uname, base, size);
 419                         first = 0;
 420                 }
 421         }
 422         return 0;
 423 }
 424
 425 /**
 426  * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 427  * in /reserved-memory matches the values supported by the current implementation,
 428  * also check if ranges property has been provided
 429  */
 430 static int __init __reserved_mem_check_root(unsigned long node)
 431 {
 432         const __be32 *prop;
 433
 434         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 435         if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 436                 return -EINVAL;
 437
 438         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 439         if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 440                 return -EINVAL;
 441
 442         prop = of_get_flat_dt_prop(node, "ranges", NULL);
 443         if (!prop)
 444                 return -EINVAL;
 445         return 0;
 446 }
 447
 448 /**
 449  * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 450  */
 451 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 452                                           int depth, void *data)
 453 {
 454         static int found;
 455         const char *status;
 456         int err;
 457
 458         if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 459                 if (__reserved_mem_check_root(node) != 0) {
 460                         pr_err("Reserved memory: unsupported node format, ignoring\n");
 461                         /* break scan */
 462                         return 1;
 463                 }
 464                 found = 1;
 465                 /* scan next node */
 466                 return 0;
 467         } else if (!found) {
 468                 /* scan next node */
 469                 return 0;
 470         } else if (found && depth < 2) {
 471                 /* scanning of /reserved-memory has been finished */
 472                 return 1;
 473         }
 474
 475         status = of_get_flat_dt_prop(node, "status", NULL);
 476         if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
 477                 return 0;
 478
 479         err = __reserved_mem_reserve_reg(node, uname);
 480         if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 481                 fdt_reserved_mem_save_node(node, uname, 0, 0);
 482
 483         /* scan next node */
 484         return 0;
 485 }
 486
 487 /**
 488  * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 489  *
 490  * This function grabs memory from early allocator for device exclusive use
 491  * defined in device tree structures. It should be called by arch specific code
 492  * once the early allocator (i.e. memblock) has been fully activated.
 493  */
 494 void __init early_init_fdt_scan_reserved_mem(void)
 495 {
 496         int n;
 497         u64 base, size;
 498
 499         if (!initial_boot_params)
 500                 return;
 501
 502         /* Reserve the dtb region */
 503         early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
 504                                           fdt_totalsize(initial_boot_params),
 505                                           0);
 506
 507         /* Process header /memreserve/ fields */
 508         for (n = 0; ; n++) {
 509                 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 510                 if (!size)
 511                         break;
 512                 early_init_dt_reserve_memory_arch(base, size, 0);
 513         }
 514
 515         of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 516         fdt_init_reserved_mem();
 517 }
 518
 519 /**
 520  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 521  * @it: callback function
 522  * @data: context data pointer
 523  *
 524  * This function is used to scan the flattened device-tree, it is
 525  * used to extract the memory information at boot before we can
 526  * unflatten the tree
 527  */
 528 int __init of_scan_flat_dt(int (*it)(unsigned long node,
 529                                      const char *uname, int depth,
 530                                      void *data),
 531                            void *data)
 532 {
 533         const void *blob = initial_boot_params;
 534         const char *pathp;
 535         int offset, rc = 0, depth = -1;
 536
 537         for (offset = fdt_next_node(blob, -1, &depth);
 538              offset >= 0 && depth >= 0 && !rc;
 539              offset = fdt_next_node(blob, offset, &depth)) {
 540
 541                 pathp = fdt_get_name(blob, offset, NULL);
 542                 if (*pathp == '/')
 543                         pathp = kbasename(pathp);
 544                 rc = it(offset, pathp, depth, data);
 545         }
 546         return rc;
 547 }
 548
 549 /**
 550  * of_get_flat_dt_root - find the root node in the flat blob
 551  */
 552 unsigned long __init of_get_flat_dt_root(void)
 553 {
 554         return 0;
 555 }
 556
 557 /**
 558  * of_get_flat_dt_size - Return the total size of the FDT
 559  */
 560 int __init of_get_flat_dt_size(void)
 561 {
 562         return fdt_totalsize(initial_boot_params);
 563 }
 564
 565 /**
 566  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 567  *
 568  * This function can be used within scan_flattened_dt callback to get
 569  * access to properties
 570  */
 571 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 572                                        int *size)
 573 {
 574         return fdt_getprop(initial_boot_params, node, name, size);
 575 }
 576
 577 /**
 578  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 579  * @node: node to test
 580  * @compat: compatible string to compare with compatible list.
 581  */
 582 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 583 {
 584         return of_fdt_is_compatible(initial_boot_params, node, compat);
 585 }
 586
 587 /**
 588  * of_flat_dt_match - Return true if node matches a list of compatible values
 589  */
 590 int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 591 {
 592         return of_fdt_match(initial_boot_params, node, compat);
 593 }
 594
 595 struct fdt_scan_status {
 596         const char *name;
 597         int namelen;
 598         int depth;
 599         int found;
 600         int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 601         void *data;
 602 };
 603
 604 const char * __init of_flat_dt_get_machine_name(void)
 605 {
 606         const char *name;
 607         unsigned long dt_root = of_get_flat_dt_root();
 608
 609         name = of_get_flat_dt_prop(dt_root, "model", NULL);
 610         if (!name)
 611                 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 612         return name;
 613 }
 614
 615 /**
 616  * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 617  *
 618  * @default_match: A machine specific ptr to return in case of no match.
 619  * @get_next_compat: callback function to return next compatible match table.
 620  *
 621  * Iterate through machine match tables to find the best match for the machine
 622  * compatible string in the FDT.
 623  */
 624 const void * __init of_flat_dt_match_machine(const void *default_match,
 625                 const void * (*get_next_compat)(const char * const**))
 626 {
 627         const void *data = NULL;
 628         const void *best_data = default_match;
 629         const char *const *compat;
 630         unsigned long dt_root;
 631         unsigned int best_score = ~1, score = 0;
 632
 633         dt_root = of_get_flat_dt_root();
 634         while ((data = get_next_compat(&compat))) {
 635                 score = of_flat_dt_match(dt_root, compat);
 636                 if (score > 0 && score < best_score) {
 637                         best_data = data;
 638                         best_score = score;
 639                 }
 640         }
 641         if (!best_data) {
 642                 const char *prop;
 643                 int size;
 644
 645                 pr_err("\n unrecognized device tree list:\n[ ");
 646
 647                 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 648                 if (prop) {
 649                         while (size > 0) {
 650                                 printk("'%s' ", prop);
 651                                 size -= strlen(prop) + 1;
 652                                 prop += strlen(prop) + 1;
 653                         }
 654                 }
 655                 printk("]\n\n");
 656                 return NULL;
 657         }
 658
 659         pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 660
 661         return best_data;
 662 }
 663
 664 #ifdef CONFIG_BLK_DEV_INITRD
 665 /**
 666  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 667  * @node: reference to node containing initrd location ('chosen')
 668  */
 669 static void __init early_init_dt_check_for_initrd(unsigned long node)
 670 {
 671         u64 start, end;
 672         int len;
 673         const __be32 *prop;
 674
 675         pr_debug("Looking for initrd properties... ");
 676
 677         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 678         if (!prop)
 679                 return;
 680         start = of_read_number(prop, len/4);
 681
 682         prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 683         if (!prop)
 684                 return;
 685         end = of_read_number(prop, len/4);
 686
 687         initrd_start = (unsigned long)__va(start);
 688         initrd_end = (unsigned long)__va(end);
 689         initrd_below_start_ok = 1;
 690
 691         pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 692                  (unsigned long long)start, (unsigned long long)end);
 693 }
 694 #else
 695 static inline void early_init_dt_check_for_initrd(unsigned long node)
 696 {
 697 }
 698 #endif /* CONFIG_BLK_DEV_INITRD */
 699
 700 #ifdef CONFIG_SERIAL_EARLYCON
 701 extern struct of_device_id __earlycon_of_table[];
 702
 703 int __init early_init_dt_scan_chosen_serial(void)
 704 {
 705         int offset;
 706         const char *p;
 707         int l;
 708         const struct of_device_id *match = __earlycon_of_table;
 709         const void *fdt = initial_boot_params;
 710
 711         offset = fdt_path_offset(fdt, "/chosen");
 712         if (offset < 0)
 713                 offset = fdt_path_offset(fdt, "/chosen@0");
 714         if (offset < 0)
 715                 return -ENOENT;
 716
 717         p = fdt_getprop(fdt, offset, "stdout-path", &l);
 718         if (!p)
 719                 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 720         if (!p || !l)
 721                 return -ENOENT;
 722
 723         /* Get the node specified by stdout-path */
 724         offset = fdt_path_offset(fdt, p);
 725         if (offset < 0)
 726                 return -ENODEV;
 727
 728         while (match->compatible) {
 729                 unsigned long addr;
 730                 if (fdt_node_check_compatible(fdt, offset, match->compatible)) {
 731                         match++;
 732                         continue;
 733                 }
 734
 735                 addr = fdt_translate_address(fdt, offset);
 736                 if (!addr)
 737                         return -ENXIO;
 738
 739                 of_setup_earlycon(addr, match->data);
 740                 return 0;
 741         }
 742         return -ENODEV;
 743 }
 744
 745 static int __init setup_of_earlycon(char *buf)
 746 {
 747         if (buf)
 748                 return 0;
 749
 750         return early_init_dt_scan_chosen_serial();
 751 }
 752 early_param("earlycon", setup_of_earlycon);
 753 #endif
 754
 755 /**
 756  * early_init_dt_scan_root - fetch the top level address and size cells
 757  */
 758 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 759                                    int depth, void *data)
 760 {
 761         const __be32 *prop;
 762
 763         if (depth != 0)
 764                 return 0;
 765
 766         dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 767         dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 768
 769         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 770         if (prop)
 771                 dt_root_size_cells = be32_to_cpup(prop);
 772         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 773
 774         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 775         if (prop)
 776                 dt_root_addr_cells = be32_to_cpup(prop);
 777         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 778
 779         /* break now */
 780         return 1;
 781 }
 782
 783 u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
 784 {
 785         const __be32 *p = *cellp;
 786
 787         *cellp = p + s;
 788         return of_read_number(p, s);
 789 }
 790
 791 /**
 792  * early_init_dt_scan_memory - Look for an parse memory nodes
 793  */
 794 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 795                                      int depth, void *data)
 796 {
 797         const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 798         const __be32 *reg, *endp;
 799         int l;
 800
 801         /* We are scanning "memory" nodes only */
 802         if (type == NULL) {
 803                 /*
 804                  * The longtrail doesn't have a device_type on the
 805                  * /memory node, so look for the node called /memory@0.
 806                  */
 807                 if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0)
 808                         return 0;
 809         } else if (strcmp(type, "memory") != 0)
 810                 return 0;
 811
 812         reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
 813         if (reg == NULL)
 814                 reg = of_get_flat_dt_prop(node, "reg", &l);
 815         if (reg == NULL)
 816                 return 0;
 817
 818         endp = reg + (l / sizeof(__be32));
 819
 820         pr_debug("memory scan node %s, reg size %d, data: %x %x %x %x,\n",
 821             uname, l, reg[0], reg[1], reg[2], reg[3]);
 822
 823         while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
 824                 u64 base, size;
 825
 826                 base = dt_mem_next_cell(dt_root_addr_cells, &reg);
 827                 size = dt_mem_next_cell(dt_root_size_cells, &reg);
 828
 829                 if (size == 0)
 830                         continue;
 831                 pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
 832                     (unsigned long long)size);
 833
 834                 early_init_dt_add_memory_arch(base, size);
 835         }
 836
 837         return 0;
 838 }
 839
 840 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
 841                                      int depth, void *data)
 842 {
 843         int l;
 844         const char *p;
 845
 846         pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
 847
 848         if (depth != 1 || !data ||
 849             (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
 850                 return 0;
 851
 852         early_init_dt_check_for_initrd(node);
 853
 854         /* Retrieve command line */
 855         p = of_get_flat_dt_prop(node, "bootargs", &l);
 856         if (p != NULL && l > 0)
 857                 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
 858
 859         /*
 860          * CONFIG_CMDLINE is meant to be a default in case nothing else
 861          * managed to set the command line, unless CONFIG_CMDLINE_FORCE
 862          * is set in which case we override whatever was found earlier.
 863          */
 864 #ifdef CONFIG_CMDLINE
 865 #ifndef CONFIG_CMDLINE_FORCE
 866         if (!((char *)data)[0])
 867 #endif
 868                 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 869 #endif /* CONFIG_CMDLINE */
 870
 871         pr_debug("Command line is: %s\n", (char*)data);
 872
 873         /* break now */
 874         return 1;
 875 }
 876
 877 #ifdef CONFIG_HAVE_MEMBLOCK
 878 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
 879 {
 880         const u64 phys_offset = __pa(PAGE_OFFSET);
 881         base &= PAGE_MASK;
 882         size &= PAGE_MASK;
 883
 884         if (sizeof(phys_addr_t) < sizeof(u64)) {
 885                 if (base > ULONG_MAX) {
 886                         pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
 887                                         base, base + size);
 888                         return;
 889                 }
 890
 891                 if (base + size > ULONG_MAX) {
 892                         pr_warning("Ignoring memory range 0x%lx - 0x%llx\n",
 893                                         ULONG_MAX, base + size);
 894                         size = ULONG_MAX - base;
 895                 }
 896         }
 897
 898         if (base + size < phys_offset) {
 899                 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
 900                            base, base + size);
 901                 return;
 902         }
 903         if (base < phys_offset) {
 904                 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
 905                            base, phys_offset);
 906                 size -= phys_offset - base;
 907                 base = phys_offset;
 908         }
 909         memblock_add(base, size);
 910 }
 911
 912 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
 913                                         phys_addr_t size, bool nomap)
 914 {
 915         if (memblock_is_region_reserved(base, size))
 916                 return -EBUSY;
 917         if (nomap)
 918                 return memblock_remove(base, size);
 919         return memblock_reserve(base, size);
 920 }
 921
 922 /*
 923  * called from unflatten_device_tree() to bootstrap devicetree itself
 924  * Architectures can override this definition if memblock isn't used
 925  */
 926 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
 927 {
 928         return __va(memblock_alloc(size, align));
 929 }
 930 #else
 931 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
 932                                         phys_addr_t size, bool nomap)
 933 {
 934         pr_err("Reserved memory not supported, ignoring range 0x%pa - 0x%pa%s\n",
 935                   &base, &size, nomap ? " (nomap)" : "");
 936         return -ENOSYS;
 937 }
 938 #endif
 939
 940 bool __init early_init_dt_scan(void *params)
 941 {
 942         if (!params)
 943                 return false;
 944
 945         /* Setup flat device-tree pointer */
 946         initial_boot_params = params;
 947
 948         /* check device tree validity */
 949         if (fdt_check_header(params)) {
 950                 initial_boot_params = NULL;
 951                 return false;
 952         }
 953
 954         /* Retrieve various information from the /chosen node */
 955         of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
 956
 957         /* Initialize {size,address}-cells info */
 958         of_scan_flat_dt(early_init_dt_scan_root, NULL);
 959
 960         /* Setup memory, calling early_init_dt_add_memory_arch */
 961         of_scan_flat_dt(early_init_dt_scan_memory, NULL);
 962
 963         return true;
 964 }
 965
 966 /**
 967  * unflatten_device_tree - create tree of device_nodes from flat blob
 968  *
 969  * unflattens the device-tree passed by the firmware, creating the
 970  * tree of struct device_node. It also fills the "name" and "type"
 971  * pointers of the nodes so the normal device-tree walking functions
 972  * can be used.
 973  */
 974 void __init unflatten_device_tree(void)
 975 {
 976         __unflatten_device_tree(initial_boot_params, &of_allnodes,
 977                                 early_init_dt_alloc_memory_arch);
 978
 979         /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
 980         of_alias_scan(early_init_dt_alloc_memory_arch);
 981 }
 982
 983 /**
 984  * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
 985  *
 986  * Copies and unflattens the device-tree passed by the firmware, creating the
 987  * tree of struct device_node. It also fills the "name" and "type"
 988  * pointers of the nodes so the normal device-tree walking functions
 989  * can be used. This should only be used when the FDT memory has not been
 990  * reserved such is the case when the FDT is built-in to the kernel init
 991  * section. If the FDT memory is reserved already then unflatten_device_tree
 992  * should be used instead.
 993  */
 994 void __init unflatten_and_copy_device_tree(void)
 995 {
 996         int size;
 997         void *dt;
 998
 999         if (!initial_boot_params) {
1000                 pr_warn("No valid device tree found, continuing without\n");
1001                 return;
1002         }
1003
1004         size = fdt_totalsize(initial_boot_params);
1005         dt = early_init_dt_alloc_memory_arch(size,
1006                                              roundup_pow_of_two(FDT_V17_SIZE));
1007
1008         if (dt) {
1009                 memcpy(dt, initial_boot_params, size);
1010                 initial_boot_params = dt;
1011         }
1012         unflatten_device_tree();
1013 }
1014
1015 #if defined(CONFIG_DEBUG_FS) && defined(DEBUG)
1016 static struct debugfs_blob_wrapper flat_dt_blob;
1017
1018 static int __init of_flat_dt_debugfs_export_fdt(void)
1019 {
1020         struct dentry *d = debugfs_create_dir("device-tree", NULL);
1021
1022         if (!d)
1023                 return -ENOENT;
1024
1025         flat_dt_blob.data = initial_boot_params;
1026         flat_dt_blob.size = fdt_totalsize(initial_boot_params);
1027
1028         d = debugfs_create_blob("flat-device-tree", S_IFREG | S_IRUSR,
1029                                 d, &flat_dt_blob);
1030         if (!d)
1031                 return -ENOENT;
1032
1033         return 0;
1034 }
1035 module_init(of_flat_dt_debugfs_export_fdt);
1036 #endif
1037
1038 #endif /* CONFIG_OF_EARLY_FLATTREE */