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/acpi.h> 12#include <linux/crash_dump.h> 13#include <linux/crc32.h> 14#include <linux/kernel.h> 15#include <linux/initrd.h> 16#include <linux/memblock.h> 17#include <linux/mutex.h> 18#include <linux/of.h> 19#include <linux/of_fdt.h> 20#include <linux/sizes.h> 21#include <linux/string.h> 22#include <linux/errno.h> 23#include <linux/slab.h> 24#include <linux/libfdt.h> 25#include <linux/debugfs.h> 26#include <linux/serial_core.h> 27#include <linux/sysfs.h> 28#include <linux/random.h> 29 30#include <asm/setup.h> /* for COMMAND_LINE_SIZE */ 31#include <asm/page.h> 32 33#include "of_private.h" 34 35/* 36 * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by 37 * cmd_dt_S_dtb in scripts/Makefile.lib 38 */ 39extern uint8_t __dtb_empty_root_begin[]; 40extern uint8_t __dtb_empty_root_end[]; 41 42/* 43 * of_fdt_limit_memory - limit the number of regions in the /memory node 44 * @limit: maximum entries 45 * 46 * Adjust the flattened device tree to have at most 'limit' number of 47 * memory entries in the /memory node. This function may be called 48 * any time after initial_boot_param is set. 49 */ 50void __init of_fdt_limit_memory(int limit) 51{ 52 int memory; 53 int len; 54 const void *val; 55 int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 56 int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 57 const __be32 *addr_prop; 58 const __be32 *size_prop; 59 int root_offset; 60 int cell_size; 61 62 root_offset = fdt_path_offset(initial_boot_params, "/"); 63 if (root_offset < 0) 64 return; 65 66 addr_prop = fdt_getprop(initial_boot_params, root_offset, 67 "#address-cells", NULL); 68 if (addr_prop) 69 nr_address_cells = fdt32_to_cpu(*addr_prop); 70 71 size_prop = fdt_getprop(initial_boot_params, root_offset, 72 "#size-cells", NULL); 73 if (size_prop) 74 nr_size_cells = fdt32_to_cpu(*size_prop); 75 76 cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells); 77 78 memory = fdt_path_offset(initial_boot_params, "/memory"); 79 if (memory > 0) { 80 val = fdt_getprop(initial_boot_params, memory, "reg", &len); 81 if (len > limit*cell_size) { 82 len = limit*cell_size; 83 pr_debug("Limiting number of entries to %d\n", limit); 84 fdt_setprop(initial_boot_params, memory, "reg", val, 85 len); 86 } 87 } 88} 89 90bool of_fdt_device_is_available(const void *blob, unsigned long node) 91{ 92 const char *status = fdt_getprop(blob, node, "status", NULL); 93 94 if (!status) 95 return true; 96 97 if (!strcmp(status, "ok") || !strcmp(status, "okay")) 98 return true; 99 100 return false; 101} 102 103static void *unflatten_dt_alloc(void **mem, unsigned long size, 104 unsigned long align) 105{ 106 void *res; 107 108 *mem = PTR_ALIGN(*mem, align); 109 res = *mem; 110 *mem += size; 111 112 return res; 113} 114 115static void populate_properties(const void *blob, 116 int offset, 117 void **mem, 118 struct device_node *np, 119 const char *nodename, 120 bool dryrun) 121{ 122 struct property *pp, **pprev = NULL; 123 int cur; 124 bool has_name = false; 125 126 pprev = &np->properties; 127 for (cur = fdt_first_property_offset(blob, offset); 128 cur >= 0; 129 cur = fdt_next_property_offset(blob, cur)) { 130 const __be32 *val; 131 const char *pname; 132 u32 sz; 133 134 val = fdt_getprop_by_offset(blob, cur, &pname, &sz); 135 if (!val) { 136 pr_warn("Cannot locate property at 0x%x\n", cur); 137 continue; 138 } 139 140 if (!pname) { 141 pr_warn("Cannot find property name at 0x%x\n", cur); 142 continue; 143 } 144 145 if (!strcmp(pname, "name")) 146 has_name = true; 147 148 pp = unflatten_dt_alloc(mem, sizeof(struct property), 149 __alignof__(struct property)); 150 if (dryrun) 151 continue; 152 153 /* We accept flattened tree phandles either in 154 * ePAPR-style "phandle" properties, or the 155 * legacy "linux,phandle" properties. If both 156 * appear and have different values, things 157 * will get weird. Don't do that. 158 */ 159 if (!strcmp(pname, "phandle") || 160 !strcmp(pname, "linux,phandle")) { 161 if (!np->phandle) 162 np->phandle = be32_to_cpup(val); 163 } 164 165 /* And we process the "ibm,phandle" property 166 * used in pSeries dynamic device tree 167 * stuff 168 */ 169 if (!strcmp(pname, "ibm,phandle")) 170 np->phandle = be32_to_cpup(val); 171 172 pp->name = (char *)pname; 173 pp->length = sz; 174 pp->value = (__be32 *)val; 175 *pprev = pp; 176 pprev = &pp->next; 177 } 178 179 /* With version 0x10 we may not have the name property, 180 * recreate it here from the unit name if absent 181 */ 182 if (!has_name) { 183 const char *p = nodename, *ps = p, *pa = NULL; 184 int len; 185 186 while (*p) { 187 if ((*p) == '@') 188 pa = p; 189 else if ((*p) == '/') 190 ps = p + 1; 191 p++; 192 } 193 194 if (pa < ps) 195 pa = p; 196 len = (pa - ps) + 1; 197 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len, 198 __alignof__(struct property)); 199 if (!dryrun) { 200 pp->name = "name"; 201 pp->length = len; 202 pp->value = pp + 1; 203 *pprev = pp; 204 memcpy(pp->value, ps, len - 1); 205 ((char *)pp->value)[len - 1] = 0; 206 pr_debug("fixed up name for %s -> %s\n", 207 nodename, (char *)pp->value); 208 } 209 } 210} 211 212static int populate_node(const void *blob, 213 int offset, 214 void **mem, 215 struct device_node *dad, 216 struct device_node **pnp, 217 bool dryrun) 218{ 219 struct device_node *np; 220 const char *pathp; 221 int len; 222 223 pathp = fdt_get_name(blob, offset, &len); 224 if (!pathp) { 225 *pnp = NULL; 226 return len; 227 } 228 229 len++; 230 231 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len, 232 __alignof__(struct device_node)); 233 if (!dryrun) { 234 char *fn; 235 of_node_init(np); 236 np->full_name = fn = ((char *)np) + sizeof(*np); 237 238 memcpy(fn, pathp, len); 239 240 if (dad != NULL) { 241 np->parent = dad; 242 np->sibling = dad->child; 243 dad->child = np; 244 } 245 } 246 247 populate_properties(blob, offset, mem, np, pathp, dryrun); 248 if (!dryrun) { 249 np->name = of_get_property(np, "name", NULL); 250 if (!np->name) 251 np->name = "<NULL>"; 252 } 253 254 *pnp = np; 255 return 0; 256} 257 258static void reverse_nodes(struct device_node *parent) 259{ 260 struct device_node *child, *next; 261 262 /* In-depth first */ 263 child = parent->child; 264 while (child) { 265 reverse_nodes(child); 266 267 child = child->sibling; 268 } 269 270 /* Reverse the nodes in the child list */ 271 child = parent->child; 272 parent->child = NULL; 273 while (child) { 274 next = child->sibling; 275 276 child->sibling = parent->child; 277 parent->child = child; 278 child = next; 279 } 280} 281 282/** 283 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree 284 * @blob: The parent device tree blob 285 * @mem: Memory chunk to use for allocating device nodes and properties 286 * @dad: Parent struct device_node 287 * @nodepp: The device_node tree created by the call 288 * 289 * Return: The size of unflattened device tree or error code 290 */ 291static int unflatten_dt_nodes(const void *blob, 292 void *mem, 293 struct device_node *dad, 294 struct device_node **nodepp) 295{ 296 struct device_node *root; 297 int offset = 0, depth = 0, initial_depth = 0; 298#define FDT_MAX_DEPTH 64 299 struct device_node *nps[FDT_MAX_DEPTH]; 300 void *base = mem; 301 bool dryrun = !base; 302 int ret; 303 304 if (nodepp) 305 *nodepp = NULL; 306 307 /* 308 * We're unflattening device sub-tree if @dad is valid. There are 309 * possibly multiple nodes in the first level of depth. We need 310 * set @depth to 1 to make fdt_next_node() happy as it bails 311 * immediately when negative @depth is found. Otherwise, the device 312 * nodes except the first one won't be unflattened successfully. 313 */ 314 if (dad) 315 depth = initial_depth = 1; 316 317 root = dad; 318 nps[depth] = dad; 319 320 for (offset = 0; 321 offset >= 0 && depth >= initial_depth; 322 offset = fdt_next_node(blob, offset, &depth)) { 323 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1)) 324 continue; 325 326 if (!IS_ENABLED(CONFIG_OF_KOBJ) && 327 !of_fdt_device_is_available(blob, offset)) 328 continue; 329 330 ret = populate_node(blob, offset, &mem, nps[depth], 331 &nps[depth+1], dryrun); 332 if (ret < 0) 333 return ret; 334 335 if (!dryrun && nodepp && !*nodepp) 336 *nodepp = nps[depth+1]; 337 if (!dryrun && !root) 338 root = nps[depth+1]; 339 } 340 341 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) { 342 pr_err("Error %d processing FDT\n", offset); 343 return -EINVAL; 344 } 345 346 /* 347 * Reverse the child list. Some drivers assumes node order matches .dts 348 * node order 349 */ 350 if (!dryrun) 351 reverse_nodes(root); 352 353 return mem - base; 354} 355 356/** 357 * __unflatten_device_tree - create tree of device_nodes from flat blob 358 * @blob: The blob to expand 359 * @dad: Parent device node 360 * @mynodes: The device_node tree created by the call 361 * @dt_alloc: An allocator that provides a virtual address to memory 362 * for the resulting tree 363 * @detached: if true set OF_DETACHED on @mynodes 364 * 365 * unflattens a device-tree, creating the tree of struct device_node. It also 366 * fills the "name" and "type" pointers of the nodes so the normal device-tree 367 * walking functions can be used. 368 * 369 * Return: NULL on failure or the memory chunk containing the unflattened 370 * device tree on success. 371 */ 372void *__unflatten_device_tree(const void *blob, 373 struct device_node *dad, 374 struct device_node **mynodes, 375 void *(*dt_alloc)(u64 size, u64 align), 376 bool detached) 377{ 378 int size; 379 void *mem; 380 int ret; 381 382 if (mynodes) 383 *mynodes = NULL; 384 385 pr_debug(" -> unflatten_device_tree()\n"); 386 387 if (!blob) { 388 pr_debug("No device tree pointer\n"); 389 return NULL; 390 } 391 392 pr_debug("Unflattening device tree:\n"); 393 pr_debug("magic: %08x\n", fdt_magic(blob)); 394 pr_debug("size: %08x\n", fdt_totalsize(blob)); 395 pr_debug("version: %08x\n", fdt_version(blob)); 396 397 if (fdt_check_header(blob)) { 398 pr_err("Invalid device tree blob header\n"); 399 return NULL; 400 } 401 402 /* First pass, scan for size */ 403 size = unflatten_dt_nodes(blob, NULL, dad, NULL); 404 if (size <= 0) 405 return NULL; 406 407 size = ALIGN(size, 4); 408 pr_debug(" size is %d, allocating...\n", size); 409 410 /* Allocate memory for the expanded device tree */ 411 mem = dt_alloc(size + 4, __alignof__(struct device_node)); 412 if (!mem) 413 return NULL; 414 415 memset(mem, 0, size); 416 417 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef); 418 419 pr_debug(" unflattening %p...\n", mem); 420 421 /* Second pass, do actual unflattening */ 422 ret = unflatten_dt_nodes(blob, mem, dad, mynodes); 423 424 if (be32_to_cpup(mem + size) != 0xdeadbeef) 425 pr_warn("End of tree marker overwritten: %08x\n", 426 be32_to_cpup(mem + size)); 427 428 if (ret <= 0) 429 return NULL; 430 431 if (detached && mynodes && *mynodes) { 432 of_node_set_flag(*mynodes, OF_DETACHED); 433 pr_debug("unflattened tree is detached\n"); 434 } 435 436 pr_debug(" <- unflatten_device_tree()\n"); 437 return mem; 438} 439 440static void *kernel_tree_alloc(u64 size, u64 align) 441{ 442 return kzalloc(size, GFP_KERNEL); 443} 444 445static DEFINE_MUTEX(of_fdt_unflatten_mutex); 446 447/** 448 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob 449 * @blob: Flat device tree blob 450 * @dad: Parent device node 451 * @mynodes: The device tree created by the call 452 * 453 * unflattens the device-tree passed by the firmware, creating the 454 * tree of struct device_node. It also fills the "name" and "type" 455 * pointers of the nodes so the normal device-tree walking functions 456 * can be used. 457 * 458 * Return: NULL on failure or the memory chunk containing the unflattened 459 * device tree on success. 460 */ 461void *of_fdt_unflatten_tree(const unsigned long *blob, 462 struct device_node *dad, 463 struct device_node **mynodes) 464{ 465 void *mem; 466 467 mutex_lock(&of_fdt_unflatten_mutex); 468 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc, 469 true); 470 mutex_unlock(&of_fdt_unflatten_mutex); 471 472 return mem; 473} 474EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree); 475 476/* Everything below here references initial_boot_params directly. */ 477int __initdata dt_root_addr_cells; 478int __initdata dt_root_size_cells; 479 480void *initial_boot_params __ro_after_init; 481 482#ifdef CONFIG_OF_EARLY_FLATTREE 483 484static u32 of_fdt_crc32; 485 486/* 487 * fdt_reserve_elfcorehdr() - reserves memory for elf core header 488 * 489 * This function reserves the memory occupied by an elf core header 490 * described in the device tree. This region contains all the 491 * information about primary kernel's core image and is used by a dump 492 * capture kernel to access the system memory on primary kernel. 493 */ 494static void __init fdt_reserve_elfcorehdr(void) 495{ 496 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size) 497 return; 498 499 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) { 500 pr_warn("elfcorehdr is overlapped\n"); 501 return; 502 } 503 504 memblock_reserve(elfcorehdr_addr, elfcorehdr_size); 505 506 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n", 507 elfcorehdr_size >> 10, elfcorehdr_addr); 508} 509 510/** 511 * early_init_fdt_scan_reserved_mem() - create reserved memory regions 512 * 513 * This function grabs memory from early allocator for device exclusive use 514 * defined in device tree structures. It should be called by arch specific code 515 * once the early allocator (i.e. memblock) has been fully activated. 516 */ 517void __init early_init_fdt_scan_reserved_mem(void) 518{ 519 int n; 520 u64 base, size; 521 522 if (!initial_boot_params) 523 return; 524 525 fdt_scan_reserved_mem(); 526 fdt_reserve_elfcorehdr(); 527 528 /* Process header /memreserve/ fields */ 529 for (n = 0; ; n++) { 530 fdt_get_mem_rsv(initial_boot_params, n, &base, &size); 531 if (!size) 532 break; 533 memblock_reserve(base, size); 534 } 535 536 fdt_init_reserved_mem(); 537} 538 539/** 540 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob 541 */ 542void __init early_init_fdt_reserve_self(void) 543{ 544 if (!initial_boot_params) 545 return; 546 547 /* Reserve the dtb region */ 548 memblock_reserve(__pa(initial_boot_params), 549 fdt_totalsize(initial_boot_params)); 550} 551 552/** 553 * of_scan_flat_dt - scan flattened tree blob and call callback on each. 554 * @it: callback function 555 * @data: context data pointer 556 * 557 * This function is used to scan the flattened device-tree, it is 558 * used to extract the memory information at boot before we can 559 * unflatten the tree 560 */ 561int __init of_scan_flat_dt(int (*it)(unsigned long node, 562 const char *uname, int depth, 563 void *data), 564 void *data) 565{ 566 const void *blob = initial_boot_params; 567 const char *pathp; 568 int offset, rc = 0, depth = -1; 569 570 if (!blob) 571 return 0; 572 573 for (offset = fdt_next_node(blob, -1, &depth); 574 offset >= 0 && depth >= 0 && !rc; 575 offset = fdt_next_node(blob, offset, &depth)) { 576 577 pathp = fdt_get_name(blob, offset, NULL); 578 rc = it(offset, pathp, depth, data); 579 } 580 return rc; 581} 582 583/** 584 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each. 585 * @parent: parent node 586 * @it: callback function 587 * @data: context data pointer 588 * 589 * This function is used to scan sub-nodes of a node. 590 */ 591int __init of_scan_flat_dt_subnodes(unsigned long parent, 592 int (*it)(unsigned long node, 593 const char *uname, 594 void *data), 595 void *data) 596{ 597 const void *blob = initial_boot_params; 598 int node; 599 600 fdt_for_each_subnode(node, blob, parent) { 601 const char *pathp; 602 int rc; 603 604 pathp = fdt_get_name(blob, node, NULL); 605 rc = it(node, pathp, data); 606 if (rc) 607 return rc; 608 } 609 return 0; 610} 611 612/** 613 * of_get_flat_dt_subnode_by_name - get the subnode by given name 614 * 615 * @node: the parent node 616 * @uname: the name of subnode 617 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none 618 */ 619 620int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) 621{ 622 return fdt_subnode_offset(initial_boot_params, node, uname); 623} 624 625/* 626 * of_get_flat_dt_root - find the root node in the flat blob 627 */ 628unsigned long __init of_get_flat_dt_root(void) 629{ 630 return 0; 631} 632 633/* 634 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr 635 * 636 * This function can be used within scan_flattened_dt callback to get 637 * access to properties 638 */ 639const void *__init of_get_flat_dt_prop(unsigned long node, const char *name, 640 int *size) 641{ 642 return fdt_getprop(initial_boot_params, node, name, size); 643} 644 645/** 646 * of_fdt_is_compatible - Return true if given node from the given blob has 647 * compat in its compatible list 648 * @blob: A device tree blob 649 * @node: node to test 650 * @compat: compatible string to compare with compatible list. 651 * 652 * Return: a non-zero value on match with smaller values returned for more 653 * specific compatible values. 654 */ 655static int of_fdt_is_compatible(const void *blob, 656 unsigned long node, const char *compat) 657{ 658 const char *cp; 659 int cplen; 660 unsigned long l, score = 0; 661 662 cp = fdt_getprop(blob, node, "compatible", &cplen); 663 if (cp == NULL) 664 return 0; 665 while (cplen > 0) { 666 score++; 667 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) 668 return score; 669 l = strlen(cp) + 1; 670 cp += l; 671 cplen -= l; 672 } 673 674 return 0; 675} 676 677/** 678 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list 679 * @node: node to test 680 * @compat: compatible string to compare with compatible list. 681 */ 682int __init of_flat_dt_is_compatible(unsigned long node, const char *compat) 683{ 684 return of_fdt_is_compatible(initial_boot_params, node, compat); 685} 686 687/* 688 * of_flat_dt_match - Return true if node matches a list of compatible values 689 */ 690static int __init of_flat_dt_match(unsigned long node, const char *const *compat) 691{ 692 unsigned int tmp, score = 0; 693 694 if (!compat) 695 return 0; 696 697 while (*compat) { 698 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat); 699 if (tmp && (score == 0 || (tmp < score))) 700 score = tmp; 701 compat++; 702 } 703 704 return score; 705} 706 707/* 708 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle 709 */ 710uint32_t __init of_get_flat_dt_phandle(unsigned long node) 711{ 712 return fdt_get_phandle(initial_boot_params, node); 713} 714 715const char * __init of_flat_dt_get_machine_name(void) 716{ 717 const char *name; 718 unsigned long dt_root = of_get_flat_dt_root(); 719 720 name = of_get_flat_dt_prop(dt_root, "model", NULL); 721 if (!name) 722 name = of_get_flat_dt_prop(dt_root, "compatible", NULL); 723 return name; 724} 725 726/** 727 * of_flat_dt_match_machine - Iterate match tables to find matching machine. 728 * 729 * @default_match: A machine specific ptr to return in case of no match. 730 * @get_next_compat: callback function to return next compatible match table. 731 * 732 * Iterate through machine match tables to find the best match for the machine 733 * compatible string in the FDT. 734 */ 735const void * __init of_flat_dt_match_machine(const void *default_match, 736 const void * (*get_next_compat)(const char * const**)) 737{ 738 const void *data = NULL; 739 const void *best_data = default_match; 740 const char *const *compat; 741 unsigned long dt_root; 742 unsigned int best_score = ~1, score = 0; 743 744 dt_root = of_get_flat_dt_root(); 745 while ((data = get_next_compat(&compat))) { 746 score = of_flat_dt_match(dt_root, compat); 747 if (score > 0 && score < best_score) { 748 best_data = data; 749 best_score = score; 750 } 751 } 752 if (!best_data) { 753 const char *prop; 754 int size; 755 756 pr_err("\n unrecognized device tree list:\n[ "); 757 758 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 759 if (prop) { 760 while (size > 0) { 761 printk("'%s' ", prop); 762 size -= strlen(prop) + 1; 763 prop += strlen(prop) + 1; 764 } 765 } 766 printk("]\n\n"); 767 return NULL; 768 } 769 770 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name()); 771 772 return best_data; 773} 774 775static void __early_init_dt_declare_initrd(unsigned long start, 776 unsigned long end) 777{ 778 /* 779 * __va() is not yet available this early on some platforms. In that 780 * case, the platform uses phys_initrd_start/phys_initrd_size instead 781 * and does the VA conversion itself. 782 */ 783 if (!IS_ENABLED(CONFIG_ARM64) && 784 !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) { 785 initrd_start = (unsigned long)__va(start); 786 initrd_end = (unsigned long)__va(end); 787 initrd_below_start_ok = 1; 788 } 789} 790 791/** 792 * early_init_dt_check_for_initrd - Decode initrd location from flat tree 793 * @node: reference to node containing initrd location ('chosen') 794 */ 795static void __init early_init_dt_check_for_initrd(unsigned long node) 796{ 797 u64 start, end; 798 int len; 799 const __be32 *prop; 800 801 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD)) 802 return; 803 804 pr_debug("Looking for initrd properties... "); 805 806 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len); 807 if (!prop) 808 return; 809 start = of_read_number(prop, len/4); 810 811 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len); 812 if (!prop) 813 return; 814 end = of_read_number(prop, len/4); 815 if (start > end) 816 return; 817 818 __early_init_dt_declare_initrd(start, end); 819 phys_initrd_start = start; 820 phys_initrd_size = end - start; 821 822 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end); 823} 824 825/** 826 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat 827 * tree 828 * @node: reference to node containing elfcorehdr location ('chosen') 829 */ 830static void __init early_init_dt_check_for_elfcorehdr(unsigned long node) 831{ 832 const __be32 *prop; 833 int len; 834 835 if (!IS_ENABLED(CONFIG_CRASH_DUMP)) 836 return; 837 838 pr_debug("Looking for elfcorehdr property... "); 839 840 prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len); 841 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells))) 842 return; 843 844 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); 845 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop); 846 847 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n", 848 elfcorehdr_addr, elfcorehdr_size); 849} 850 851static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; 852 853/* 854 * The main usage of linux,usable-memory-range is for crash dump kernel. 855 * Originally, the number of usable-memory regions is one. Now there may 856 * be two regions, low region and high region. 857 * To make compatibility with existing user-space and older kdump, the low 858 * region is always the last range of linux,usable-memory-range if exist. 859 */ 860#define MAX_USABLE_RANGES 2 861 862/** 863 * early_init_dt_check_for_usable_mem_range - Decode usable memory range 864 * location from flat tree 865 */ 866void __init early_init_dt_check_for_usable_mem_range(void) 867{ 868 struct memblock_region rgn[MAX_USABLE_RANGES] = {0}; 869 const __be32 *prop, *endp; 870 int len, i; 871 unsigned long node = chosen_node_offset; 872 873 if ((long)node < 0) 874 return; 875 876 pr_debug("Looking for usable-memory-range property... "); 877 878 prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); 879 if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells))) 880 return; 881 882 endp = prop + (len / sizeof(__be32)); 883 for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) { 884 rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop); 885 rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop); 886 887 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n", 888 i, &rgn[i].base, &rgn[i].size); 889 } 890 891 memblock_cap_memory_range(rgn[0].base, rgn[0].size); 892 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++) 893 memblock_add(rgn[i].base, rgn[i].size); 894} 895 896#ifdef CONFIG_SERIAL_EARLYCON 897 898int __init early_init_dt_scan_chosen_stdout(void) 899{ 900 int offset; 901 const char *p, *q, *options = NULL; 902 int l; 903 const struct earlycon_id *match; 904 const void *fdt = initial_boot_params; 905 int ret; 906 907 offset = fdt_path_offset(fdt, "/chosen"); 908 if (offset < 0) 909 offset = fdt_path_offset(fdt, "/chosen@0"); 910 if (offset < 0) 911 return -ENOENT; 912 913 p = fdt_getprop(fdt, offset, "stdout-path", &l); 914 if (!p) 915 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l); 916 if (!p || !l) 917 return -ENOENT; 918 919 q = strchrnul(p, ':'); 920 if (*q != '\0') 921 options = q + 1; 922 l = q - p; 923 924 /* Get the node specified by stdout-path */ 925 offset = fdt_path_offset_namelen(fdt, p, l); 926 if (offset < 0) { 927 pr_warn("earlycon: stdout-path %.*s not found\n", l, p); 928 return 0; 929 } 930 931 for (match = __earlycon_table; match < __earlycon_table_end; match++) { 932 if (!match->compatible[0]) 933 continue; 934 935 if (fdt_node_check_compatible(fdt, offset, match->compatible)) 936 continue; 937 938 ret = of_setup_earlycon(match, offset, options); 939 if (!ret || ret == -EALREADY) 940 return 0; 941 } 942 return -ENODEV; 943} 944#endif 945 946/* 947 * early_init_dt_scan_root - fetch the top level address and size cells 948 */ 949int __init early_init_dt_scan_root(void) 950{ 951 const __be32 *prop; 952 const void *fdt = initial_boot_params; 953 int node = fdt_path_offset(fdt, "/"); 954 955 if (node < 0) 956 return -ENODEV; 957 958 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 959 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 960 961 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 962 if (prop) 963 dt_root_size_cells = be32_to_cpup(prop); 964 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells); 965 966 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 967 if (prop) 968 dt_root_addr_cells = be32_to_cpup(prop); 969 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells); 970 971 return 0; 972} 973 974u64 __init dt_mem_next_cell(int s, const __be32 **cellp) 975{ 976 const __be32 *p = *cellp; 977 978 *cellp = p + s; 979 return of_read_number(p, s); 980} 981 982/* 983 * early_init_dt_scan_memory - Look for and parse memory nodes 984 */ 985int __init early_init_dt_scan_memory(void) 986{ 987 int node, found_memory = 0; 988 const void *fdt = initial_boot_params; 989 990 fdt_for_each_subnode(node, fdt, 0) { 991 const char *type = of_get_flat_dt_prop(node, "device_type", NULL); 992 const __be32 *reg, *endp; 993 int l; 994 bool hotpluggable; 995 996 /* We are scanning "memory" nodes only */ 997 if (type == NULL || strcmp(type, "memory") != 0) 998 continue; 999 1000 if (!of_fdt_device_is_available(fdt, node)) 1001 continue; 1002 1003 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l); 1004 if (reg == NULL) 1005 reg = of_get_flat_dt_prop(node, "reg", &l); 1006 if (reg == NULL) 1007 continue; 1008 1009 endp = reg + (l / sizeof(__be32)); 1010 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL); 1011 1012 pr_debug("memory scan node %s, reg size %d,\n", 1013 fdt_get_name(fdt, node, NULL), l); 1014 1015 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) { 1016 u64 base, size; 1017 1018 base = dt_mem_next_cell(dt_root_addr_cells, ®); 1019 size = dt_mem_next_cell(dt_root_size_cells, ®); 1020 1021 if (size == 0) 1022 continue; 1023 pr_debug(" - %llx, %llx\n", base, size); 1024 1025 early_init_dt_add_memory_arch(base, size); 1026 1027 found_memory = 1; 1028 1029 if (!hotpluggable) 1030 continue; 1031 1032 if (memblock_mark_hotplug(base, size)) 1033 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n", 1034 base, base + size); 1035 } 1036 } 1037 return found_memory; 1038} 1039 1040int __init early_init_dt_scan_chosen(char *cmdline) 1041{ 1042 int l, node; 1043 const char *p; 1044 const void *rng_seed; 1045 const void *fdt = initial_boot_params; 1046 1047 node = fdt_path_offset(fdt, "/chosen"); 1048 if (node < 0) 1049 node = fdt_path_offset(fdt, "/chosen@0"); 1050 if (node < 0) 1051 /* Handle the cmdline config options even if no /chosen node */ 1052 goto handle_cmdline; 1053 1054 chosen_node_offset = node; 1055 1056 early_init_dt_check_for_initrd(node); 1057 early_init_dt_check_for_elfcorehdr(node); 1058 1059 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l); 1060 if (rng_seed && l > 0) { 1061 add_bootloader_randomness(rng_seed, l); 1062 1063 /* try to clear seed so it won't be found. */ 1064 fdt_nop_property(initial_boot_params, node, "rng-seed"); 1065 1066 /* update CRC check value */ 1067 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1068 fdt_totalsize(initial_boot_params)); 1069 } 1070 1071 /* Retrieve command line */ 1072 p = of_get_flat_dt_prop(node, "bootargs", &l); 1073 if (p != NULL && l > 0) 1074 strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE)); 1075 1076handle_cmdline: 1077 /* 1078 * CONFIG_CMDLINE is meant to be a default in case nothing else 1079 * managed to set the command line, unless CONFIG_CMDLINE_FORCE 1080 * is set in which case we override whatever was found earlier. 1081 */ 1082#ifdef CONFIG_CMDLINE 1083#if defined(CONFIG_CMDLINE_EXTEND) 1084 strlcat(cmdline, " ", COMMAND_LINE_SIZE); 1085 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1086#elif defined(CONFIG_CMDLINE_FORCE) 1087 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1088#else 1089 /* No arguments from boot loader, use kernel's cmdl*/ 1090 if (!((char *)cmdline)[0]) 1091 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1092#endif 1093#endif /* CONFIG_CMDLINE */ 1094 1095 pr_debug("Command line is: %s\n", (char *)cmdline); 1096 1097 return 0; 1098} 1099 1100#ifndef MIN_MEMBLOCK_ADDR 1101#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET) 1102#endif 1103#ifndef MAX_MEMBLOCK_ADDR 1104#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0) 1105#endif 1106 1107void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) 1108{ 1109 const u64 phys_offset = MIN_MEMBLOCK_ADDR; 1110 1111 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { 1112 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1113 base, base + size); 1114 return; 1115 } 1116 1117 if (!PAGE_ALIGNED(base)) { 1118 size -= PAGE_SIZE - (base & ~PAGE_MASK); 1119 base = PAGE_ALIGN(base); 1120 } 1121 size &= PAGE_MASK; 1122 1123 if (base > MAX_MEMBLOCK_ADDR) { 1124 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1125 base, base + size); 1126 return; 1127 } 1128 1129 if (base + size - 1 > MAX_MEMBLOCK_ADDR) { 1130 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", 1131 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size); 1132 size = MAX_MEMBLOCK_ADDR - base + 1; 1133 } 1134 1135 if (base + size < phys_offset) { 1136 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1137 base, base + size); 1138 return; 1139 } 1140 if (base < phys_offset) { 1141 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", 1142 base, phys_offset); 1143 size -= phys_offset - base; 1144 base = phys_offset; 1145 } 1146 memblock_add(base, size); 1147} 1148 1149static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align) 1150{ 1151 void *ptr = memblock_alloc(size, align); 1152 1153 if (!ptr) 1154 panic("%s: Failed to allocate %llu bytes align=0x%llx\n", 1155 __func__, size, align); 1156 1157 return ptr; 1158} 1159 1160bool __init early_init_dt_verify(void *params) 1161{ 1162 if (!params) 1163 return false; 1164 1165 /* check device tree validity */ 1166 if (fdt_check_header(params)) 1167 return false; 1168 1169 /* Setup flat device-tree pointer */ 1170 initial_boot_params = params; 1171 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1172 fdt_totalsize(initial_boot_params)); 1173 return true; 1174} 1175 1176 1177void __init early_init_dt_scan_nodes(void) 1178{ 1179 int rc; 1180 1181 /* Initialize {size,address}-cells info */ 1182 early_init_dt_scan_root(); 1183 1184 /* Retrieve various information from the /chosen node */ 1185 rc = early_init_dt_scan_chosen(boot_command_line); 1186 if (rc) 1187 pr_warn("No chosen node found, continuing without\n"); 1188 1189 /* Setup memory, calling early_init_dt_add_memory_arch */ 1190 early_init_dt_scan_memory(); 1191 1192 /* Handle linux,usable-memory-range property */ 1193 early_init_dt_check_for_usable_mem_range(); 1194} 1195 1196bool __init early_init_dt_scan(void *params) 1197{ 1198 bool status; 1199 1200 status = early_init_dt_verify(params); 1201 if (!status) 1202 return false; 1203 1204 early_init_dt_scan_nodes(); 1205 return true; 1206} 1207 1208static void *__init copy_device_tree(void *fdt) 1209{ 1210 int size; 1211 void *dt; 1212 1213 size = fdt_totalsize(fdt); 1214 dt = early_init_dt_alloc_memory_arch(size, 1215 roundup_pow_of_two(FDT_V17_SIZE)); 1216 1217 if (dt) 1218 memcpy(dt, fdt, size); 1219 1220 return dt; 1221} 1222 1223/** 1224 * unflatten_device_tree - create tree of device_nodes from flat blob 1225 * 1226 * unflattens the device-tree passed by the firmware, creating the 1227 * tree of struct device_node. It also fills the "name" and "type" 1228 * pointers of the nodes so the normal device-tree walking functions 1229 * can be used. 1230 */ 1231void __init unflatten_device_tree(void) 1232{ 1233 void *fdt = initial_boot_params; 1234 1235 /* Don't use the bootloader provided DTB if ACPI is enabled */ 1236 if (!acpi_disabled) 1237 fdt = NULL; 1238 1239 /* 1240 * Populate an empty root node when ACPI is enabled or bootloader 1241 * doesn't provide one. 1242 */ 1243 if (!fdt) { 1244 fdt = (void *) __dtb_empty_root_begin; 1245 /* fdt_totalsize() will be used for copy size */ 1246 if (fdt_totalsize(fdt) > 1247 __dtb_empty_root_end - __dtb_empty_root_begin) { 1248 pr_err("invalid size in dtb_empty_root\n"); 1249 return; 1250 } 1251 of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt)); 1252 fdt = copy_device_tree(fdt); 1253 } 1254 1255 __unflatten_device_tree(fdt, NULL, &of_root, 1256 early_init_dt_alloc_memory_arch, false); 1257 1258 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ 1259 of_alias_scan(early_init_dt_alloc_memory_arch); 1260 1261 unittest_unflatten_overlay_base(); 1262} 1263 1264/** 1265 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob 1266 * 1267 * Copies and unflattens the device-tree passed by the firmware, creating the 1268 * tree of struct device_node. It also fills the "name" and "type" 1269 * pointers of the nodes so the normal device-tree walking functions 1270 * can be used. This should only be used when the FDT memory has not been 1271 * reserved such is the case when the FDT is built-in to the kernel init 1272 * section. If the FDT memory is reserved already then unflatten_device_tree 1273 * should be used instead. 1274 */ 1275void __init unflatten_and_copy_device_tree(void) 1276{ 1277 if (initial_boot_params) 1278 initial_boot_params = copy_device_tree(initial_boot_params); 1279 1280 unflatten_device_tree(); 1281} 1282 1283#ifdef CONFIG_SYSFS 1284static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj, 1285 struct bin_attribute *bin_attr, 1286 char *buf, loff_t off, size_t count) 1287{ 1288 memcpy(buf, initial_boot_params + off, count); 1289 return count; 1290} 1291 1292static int __init of_fdt_raw_init(void) 1293{ 1294 static struct bin_attribute of_fdt_raw_attr = 1295 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0); 1296 1297 if (!initial_boot_params) 1298 return 0; 1299 1300 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params, 1301 fdt_totalsize(initial_boot_params))) { 1302 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n"); 1303 return 0; 1304 } 1305 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params); 1306 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr); 1307} 1308late_initcall(of_fdt_raw_init); 1309#endif 1310 1311#endif /* CONFIG_OF_EARLY_FLATTREE */ 1312