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/crash_dump.h> 12 #include <linux/crc32.h> 13 #include <linux/kernel.h> 14 #include <linux/initrd.h> 15 #include <linux/memblock.h> 16 #include <linux/mutex.h> 17 #include <linux/of.h> 18 #include <linux/of_fdt.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 #include <linux/kexec_handover.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_wrap_S_dtb in scripts/Makefile.dtbs 38 */ 39 extern uint8_t __dtb_empty_root_begin[]; 40 extern 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 */ 50 void __init of_fdt_limit_memory(int limit) 51 { 52 int memory; 53 int len; 54 const void *val; 55 int cell_size = sizeof(uint32_t)*(dt_root_addr_cells + dt_root_size_cells); 56 57 memory = fdt_path_offset(initial_boot_params, "/memory"); 58 if (memory > 0) { 59 val = fdt_getprop(initial_boot_params, memory, "reg", &len); 60 if (len > limit*cell_size) { 61 len = limit*cell_size; 62 pr_debug("Limiting number of entries to %d\n", limit); 63 fdt_setprop(initial_boot_params, memory, "reg", val, 64 len); 65 } 66 } 67 } 68 69 bool of_fdt_device_is_available(const void *blob, unsigned long node) 70 { 71 const char *status = fdt_stringlist_get(blob, node, "status", 0, NULL); 72 73 if (!status) 74 return true; 75 76 if (!strcmp(status, "ok") || !strcmp(status, "okay")) 77 return true; 78 79 return false; 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 static void populate_properties(const void *blob, 95 int offset, 96 void **mem, 97 struct device_node *np, 98 const char *nodename, 99 bool dryrun) 100 { 101 struct property *pp, **pprev = NULL; 102 int cur; 103 bool has_name = false; 104 105 pprev = &np->properties; 106 for (cur = fdt_first_property_offset(blob, offset); 107 cur >= 0; 108 cur = fdt_next_property_offset(blob, cur)) { 109 const __be32 *val; 110 const char *pname; 111 u32 sz; 112 113 val = fdt_getprop_by_offset(blob, cur, &pname, &sz); 114 if (!val) { 115 pr_warn("Cannot locate property at 0x%x\n", cur); 116 continue; 117 } 118 119 if (!pname) { 120 pr_warn("Cannot find property name at 0x%x\n", cur); 121 continue; 122 } 123 124 if (!strcmp(pname, "name")) 125 has_name = true; 126 127 pp = unflatten_dt_alloc(mem, sizeof(struct property), 128 __alignof__(struct property)); 129 if (dryrun) 130 continue; 131 132 /* We accept flattened tree phandles either in 133 * ePAPR-style "phandle" properties, or the 134 * legacy "linux,phandle" properties. If both 135 * appear and have different values, things 136 * will get weird. Don't do that. 137 */ 138 if (!strcmp(pname, "phandle") || 139 !strcmp(pname, "linux,phandle")) { 140 if (!np->phandle) 141 np->phandle = be32_to_cpup(val); 142 } 143 144 /* And we process the "ibm,phandle" property 145 * used in pSeries dynamic device tree 146 * stuff 147 */ 148 if (IS_ENABLED(CONFIG_PPC_PSERIES) && !strcmp(pname, "ibm,phandle")) 149 np->phandle = be32_to_cpup(val); 150 151 pp->name = (char *)pname; 152 pp->length = sz; 153 pp->value = (__be32 *)val; 154 *pprev = pp; 155 pprev = &pp->next; 156 } 157 158 /* With version 0x10 we may not have the name property, 159 * recreate it here from the unit name if absent 160 */ 161 if (!has_name) { 162 const char *p = nodename, *ps = p, *pa = NULL; 163 int len; 164 165 while (*p) { 166 if ((*p) == '@') 167 pa = p; 168 else if ((*p) == '/') 169 ps = p + 1; 170 p++; 171 } 172 173 if (pa < ps) 174 pa = p; 175 len = (pa - ps) + 1; 176 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len, 177 __alignof__(struct property)); 178 if (!dryrun) { 179 pp->name = "name"; 180 pp->length = len; 181 pp->value = pp + 1; 182 *pprev = pp; 183 memcpy(pp->value, ps, len - 1); 184 ((char *)pp->value)[len - 1] = 0; 185 pr_debug("fixed up name for %s -> %s\n", 186 nodename, (char *)pp->value); 187 } 188 } 189 } 190 191 static int populate_node(const void *blob, 192 int offset, 193 void **mem, 194 struct device_node *dad, 195 struct device_node **pnp, 196 bool dryrun) 197 { 198 struct device_node *np; 199 const char *pathp; 200 int len; 201 202 pathp = fdt_get_name(blob, offset, &len); 203 if (!pathp) { 204 *pnp = NULL; 205 return len; 206 } 207 208 len++; 209 210 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len, 211 __alignof__(struct device_node)); 212 if (!dryrun) { 213 char *fn; 214 of_node_init(np); 215 np->full_name = fn = ((char *)np) + sizeof(*np); 216 217 memcpy(fn, pathp, len); 218 219 if (dad != NULL) { 220 np->parent = dad; 221 np->sibling = dad->child; 222 dad->child = np; 223 } 224 } 225 226 populate_properties(blob, offset, mem, np, pathp, dryrun); 227 if (!dryrun) { 228 np->name = of_get_property(np, "name", NULL); 229 if (!np->name) 230 np->name = "<NULL>"; 231 } 232 233 *pnp = np; 234 return 0; 235 } 236 237 static void reverse_nodes(struct device_node *parent) 238 { 239 struct device_node *child, *next; 240 241 /* In-depth first */ 242 child = parent->child; 243 while (child) { 244 reverse_nodes(child); 245 246 child = child->sibling; 247 } 248 249 /* Reverse the nodes in the child list */ 250 child = parent->child; 251 parent->child = NULL; 252 while (child) { 253 next = child->sibling; 254 255 child->sibling = parent->child; 256 parent->child = child; 257 child = next; 258 } 259 } 260 261 /** 262 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree 263 * @blob: The parent device tree blob 264 * @mem: Memory chunk to use for allocating device nodes and properties 265 * @dad: Parent struct device_node 266 * @nodepp: The device_node tree created by the call 267 * 268 * Return: The size of unflattened device tree or error code 269 */ 270 static int unflatten_dt_nodes(const void *blob, 271 void *mem, 272 struct device_node *dad, 273 struct device_node **nodepp) 274 { 275 struct device_node *root; 276 int offset = 0, depth = 0, initial_depth = 0; 277 #define FDT_MAX_DEPTH 64 278 struct device_node *nps[FDT_MAX_DEPTH]; 279 void *base = mem; 280 bool dryrun = !base; 281 int ret; 282 283 if (nodepp) 284 *nodepp = NULL; 285 286 /* 287 * We're unflattening device sub-tree if @dad is valid. There are 288 * possibly multiple nodes in the first level of depth. We need 289 * set @depth to 1 to make fdt_next_node() happy as it bails 290 * immediately when negative @depth is found. Otherwise, the device 291 * nodes except the first one won't be unflattened successfully. 292 */ 293 if (dad) 294 depth = initial_depth = 1; 295 296 root = dad; 297 nps[depth] = dad; 298 299 for (offset = 0; 300 offset >= 0 && depth >= initial_depth; 301 offset = fdt_next_node(blob, offset, &depth)) { 302 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1)) 303 continue; 304 305 if (!IS_ENABLED(CONFIG_OF_KOBJ) && 306 !of_fdt_device_is_available(blob, offset)) 307 continue; 308 309 ret = populate_node(blob, offset, &mem, nps[depth], 310 &nps[depth+1], dryrun); 311 if (ret < 0) 312 return ret; 313 314 if (!dryrun && nodepp && !*nodepp) 315 *nodepp = nps[depth+1]; 316 if (!dryrun && !root) 317 root = nps[depth+1]; 318 } 319 320 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) { 321 pr_err("Error %d processing FDT\n", offset); 322 return -EINVAL; 323 } 324 325 /* 326 * Reverse the child list. Some drivers assumes node order matches .dts 327 * node order 328 */ 329 if (!dryrun) 330 reverse_nodes(root); 331 332 return mem - base; 333 } 334 335 /** 336 * __unflatten_device_tree - create tree of device_nodes from flat blob 337 * @blob: The blob to expand 338 * @dad: Parent device node 339 * @mynodes: The device_node tree created by the call 340 * @dt_alloc: An allocator that provides a virtual address to memory 341 * for the resulting tree 342 * @detached: if true set OF_DETACHED on @mynodes 343 * 344 * unflattens a device-tree, creating the tree of struct device_node. It also 345 * fills the "name" and "type" pointers of the nodes so the normal device-tree 346 * walking functions can be used. 347 * 348 * Return: NULL on failure or the memory chunk containing the unflattened 349 * device tree on success. 350 */ 351 void *__unflatten_device_tree(const void *blob, 352 struct device_node *dad, 353 struct device_node **mynodes, 354 void *(*dt_alloc)(u64 size, u64 align), 355 bool detached) 356 { 357 int size; 358 void *mem; 359 int ret; 360 361 if (mynodes) 362 *mynodes = NULL; 363 364 pr_debug(" -> unflatten_device_tree()\n"); 365 366 if (!blob) { 367 pr_debug("No device tree pointer\n"); 368 return NULL; 369 } 370 371 pr_debug("Unflattening device tree:\n"); 372 pr_debug("magic: %08x\n", fdt_magic(blob)); 373 pr_debug("size: %08x\n", fdt_totalsize(blob)); 374 pr_debug("version: %08x\n", fdt_version(blob)); 375 376 if (fdt_check_header(blob)) { 377 pr_err("Invalid device tree blob header\n"); 378 return NULL; 379 } 380 381 /* First pass, scan for size */ 382 size = unflatten_dt_nodes(blob, NULL, dad, NULL); 383 if (size <= 0) 384 return NULL; 385 386 size = ALIGN(size, 4); 387 pr_debug(" size is %d, allocating...\n", size); 388 389 /* Allocate memory for the expanded device tree */ 390 mem = dt_alloc(size + 4, __alignof__(struct device_node)); 391 if (!mem) 392 return NULL; 393 394 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef); 395 396 pr_debug(" unflattening %p...\n", mem); 397 398 /* Second pass, do actual unflattening */ 399 ret = unflatten_dt_nodes(blob, mem, dad, mynodes); 400 401 if (be32_to_cpup(mem + size) != 0xdeadbeef) 402 pr_warn("End of tree marker overwritten: %08x\n", 403 be32_to_cpup(mem + size)); 404 405 if (ret <= 0) 406 return NULL; 407 408 if (detached && mynodes && *mynodes) { 409 of_node_set_flag(*mynodes, OF_DETACHED); 410 pr_debug("unflattened tree is detached\n"); 411 } 412 413 pr_debug(" <- unflatten_device_tree()\n"); 414 return mem; 415 } 416 417 static void *kernel_tree_alloc(u64 size, u64 align) 418 { 419 return kzalloc(size, GFP_KERNEL); 420 } 421 422 static DEFINE_MUTEX(of_fdt_unflatten_mutex); 423 424 /** 425 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob 426 * @blob: Flat device tree blob 427 * @dad: Parent device node 428 * @mynodes: The device tree created by the call 429 * 430 * unflattens the device-tree passed by the firmware, creating the 431 * tree of struct device_node. It also fills the "name" and "type" 432 * pointers of the nodes so the normal device-tree walking functions 433 * can be used. 434 * 435 * Return: NULL on failure or the memory chunk containing the unflattened 436 * device tree on success. 437 */ 438 void *of_fdt_unflatten_tree(const unsigned long *blob, 439 struct device_node *dad, 440 struct device_node **mynodes) 441 { 442 void *mem; 443 444 mutex_lock(&of_fdt_unflatten_mutex); 445 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc, 446 true); 447 mutex_unlock(&of_fdt_unflatten_mutex); 448 449 return mem; 450 } 451 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree); 452 453 /* Everything below here references initial_boot_params directly. */ 454 int __initdata dt_root_addr_cells; 455 int __initdata dt_root_size_cells; 456 457 void *initial_boot_params __ro_after_init; 458 phys_addr_t initial_boot_params_pa __ro_after_init; 459 460 #ifdef CONFIG_OF_EARLY_FLATTREE 461 462 static u32 of_fdt_crc32; 463 464 /* 465 * fdt_reserve_elfcorehdr() - reserves memory for elf core header 466 * 467 * This function reserves the memory occupied by an elf core header 468 * described in the device tree. This region contains all the 469 * information about primary kernel's core image and is used by a dump 470 * capture kernel to access the system memory on primary kernel. 471 */ 472 static void __init fdt_reserve_elfcorehdr(void) 473 { 474 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size) 475 return; 476 477 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) { 478 pr_warn("elfcorehdr is overlapped\n"); 479 return; 480 } 481 482 memblock_reserve(elfcorehdr_addr, elfcorehdr_size); 483 484 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n", 485 elfcorehdr_size >> 10, elfcorehdr_addr); 486 } 487 488 /** 489 * early_init_fdt_scan_reserved_mem() - create reserved memory regions 490 * 491 * This function grabs memory from early allocator for device exclusive use 492 * defined in device tree structures. It should be called by arch specific code 493 * once the early allocator (i.e. memblock) has been fully activated. 494 */ 495 void __init early_init_fdt_scan_reserved_mem(void) 496 { 497 int n; 498 int res; 499 u64 base, size; 500 501 if (!initial_boot_params) 502 return; 503 504 fdt_reserve_elfcorehdr(); 505 fdt_scan_reserved_mem(); 506 507 /* Process header /memreserve/ fields */ 508 for (n = 0; ; n++) { 509 res = fdt_get_mem_rsv(initial_boot_params, n, &base, &size); 510 if (res) { 511 pr_err("Invalid memory reservation block index %d\n", n); 512 break; 513 } 514 if (!size) 515 break; 516 memblock_reserve(base, size); 517 } 518 } 519 520 /** 521 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob 522 */ 523 void __init early_init_fdt_reserve_self(void) 524 { 525 if (!initial_boot_params) 526 return; 527 528 /* Reserve the dtb region */ 529 memblock_reserve(__pa(initial_boot_params), 530 fdt_totalsize(initial_boot_params)); 531 } 532 533 /** 534 * of_scan_flat_dt - scan flattened tree blob and call callback on each. 535 * @it: callback function 536 * @data: context data pointer 537 * 538 * This function is used to scan the flattened device-tree, it is 539 * used to extract the memory information at boot before we can 540 * unflatten the tree 541 */ 542 int __init of_scan_flat_dt(int (*it)(unsigned long node, 543 const char *uname, int depth, 544 void *data), 545 void *data) 546 { 547 const void *blob = initial_boot_params; 548 const char *pathp; 549 int offset, rc = 0, depth = -1; 550 551 if (!blob) 552 return 0; 553 554 for (offset = fdt_next_node(blob, -1, &depth); 555 offset >= 0 && depth >= 0 && !rc; 556 offset = fdt_next_node(blob, offset, &depth)) { 557 558 pathp = fdt_get_name(blob, offset, NULL); 559 rc = it(offset, pathp, depth, data); 560 } 561 return rc; 562 } 563 564 /** 565 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each. 566 * @parent: parent node 567 * @it: callback function 568 * @data: context data pointer 569 * 570 * This function is used to scan sub-nodes of a node. 571 */ 572 int __init of_scan_flat_dt_subnodes(unsigned long parent, 573 int (*it)(unsigned long node, 574 const char *uname, 575 void *data), 576 void *data) 577 { 578 const void *blob = initial_boot_params; 579 int node; 580 581 fdt_for_each_subnode(node, blob, parent) { 582 const char *pathp; 583 int rc; 584 585 pathp = fdt_get_name(blob, node, NULL); 586 rc = it(node, pathp, data); 587 if (rc) 588 return rc; 589 } 590 return 0; 591 } 592 593 /** 594 * of_get_flat_dt_subnode_by_name - get the subnode by given name 595 * 596 * @node: the parent node 597 * @uname: the name of subnode 598 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none 599 */ 600 601 int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) 602 { 603 return fdt_subnode_offset(initial_boot_params, node, uname); 604 } 605 606 /* 607 * of_get_flat_dt_root - find the root node in the flat blob 608 */ 609 unsigned long __init of_get_flat_dt_root(void) 610 { 611 return 0; 612 } 613 614 /* 615 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr 616 * 617 * This function can be used within scan_flattened_dt callback to get 618 * access to properties 619 */ 620 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name, 621 int *size) 622 { 623 return fdt_getprop(initial_boot_params, node, name, size); 624 } 625 626 const __be32 *__init of_flat_dt_get_addr_size_prop(unsigned long node, 627 const char *name, 628 int *entries) 629 { 630 const __be32 *prop; 631 int len, elen = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32); 632 633 prop = of_get_flat_dt_prop(node, name, &len); 634 if (!prop || len % elen) { 635 *entries = 0; 636 return NULL; 637 } 638 639 *entries = len / elen; 640 return prop; 641 } 642 643 bool __init of_flat_dt_get_addr_size(unsigned long node, const char *name, 644 u64 *addr, u64 *size) 645 { 646 const __be32 *prop; 647 int entries; 648 649 prop = of_flat_dt_get_addr_size_prop(node, name, &entries); 650 if (!prop || entries != 1) 651 return false; 652 653 of_flat_dt_read_addr_size(prop, 0, addr, size); 654 return true; 655 } 656 657 void __init of_flat_dt_read_addr_size(const __be32 *prop, int entry_index, 658 u64 *addr, u64 *size) 659 { 660 int entry_cells = dt_root_addr_cells + dt_root_size_cells; 661 prop += entry_cells * entry_index; 662 663 *addr = dt_mem_next_cell(dt_root_addr_cells, &prop); 664 *size = dt_mem_next_cell(dt_root_size_cells, &prop); 665 } 666 667 /** 668 * of_fdt_is_compatible - Return true if given node from the given blob has 669 * compat in its compatible list 670 * @blob: A device tree blob 671 * @node: node to test 672 * @compat: compatible string to compare with compatible list. 673 * 674 * Return: a non-zero value on match with smaller values returned for more 675 * specific compatible values. 676 */ 677 static int of_fdt_is_compatible(const void *blob, 678 unsigned long node, const char *compat) 679 { 680 const char *cp; 681 int idx = 0, score = 0; 682 683 while ((cp = fdt_stringlist_get(blob, node, "compatible", idx++, NULL))) { 684 score++; 685 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) 686 return score; 687 } 688 689 return 0; 690 } 691 692 /** 693 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list 694 * @node: node to test 695 * @compat: compatible string to compare with compatible list. 696 */ 697 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat) 698 { 699 return of_fdt_is_compatible(initial_boot_params, node, compat); 700 } 701 702 /* 703 * of_flat_dt_match - Return true if node matches a list of compatible values 704 */ 705 static int __init of_flat_dt_match(unsigned long node, const char *const *compat) 706 { 707 unsigned int tmp, score = 0; 708 709 if (!compat) 710 return 0; 711 712 while (*compat) { 713 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat); 714 if (tmp && (score == 0 || (tmp < score))) 715 score = tmp; 716 compat++; 717 } 718 719 return score; 720 } 721 722 /* 723 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle 724 */ 725 uint32_t __init of_get_flat_dt_phandle(unsigned long node) 726 { 727 return fdt_get_phandle(initial_boot_params, node); 728 } 729 730 const char * __init of_flat_dt_get_machine_name(void) 731 { 732 const char *name; 733 unsigned long dt_root = of_get_flat_dt_root(); 734 735 name = fdt_stringlist_get(initial_boot_params, dt_root, "model", 0, NULL); 736 if (!name) 737 name = fdt_stringlist_get(initial_boot_params, dt_root, 738 "compatible", 0, NULL); 739 return name; 740 } 741 742 /** 743 * of_flat_dt_match_machine - Iterate match tables to find matching machine. 744 * 745 * @default_match: A machine specific ptr to return in case of no match. 746 * @get_next_compat: callback function to return next compatible match table. 747 * 748 * Iterate through machine match tables to find the best match for the machine 749 * compatible string in the FDT. 750 */ 751 const void * __init of_flat_dt_match_machine(const void *default_match, 752 const void * (*get_next_compat)(const char * const**)) 753 { 754 const void *data = NULL; 755 const void *best_data = default_match; 756 const char *const *compat; 757 unsigned long dt_root; 758 unsigned int best_score = ~1, score = 0; 759 760 dt_root = of_get_flat_dt_root(); 761 while ((data = get_next_compat(&compat))) { 762 score = of_flat_dt_match(dt_root, compat); 763 if (score > 0 && score < best_score) { 764 best_data = data; 765 best_score = score; 766 } 767 } 768 if (!best_data) { 769 const char *prop; 770 int idx = 0, size; 771 772 pr_err("\n unrecognized device tree list:\n[ "); 773 774 while ((prop = fdt_stringlist_get(initial_boot_params, dt_root, 775 "compatible", idx++, &size))) 776 pr_err("'%s' ", prop); 777 pr_err("]\n\n"); 778 return NULL; 779 } 780 781 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name()); 782 783 return best_data; 784 } 785 786 static void __early_init_dt_declare_initrd(unsigned long start, 787 unsigned long end) 788 { 789 /* 790 * __va() is not yet available this early on some platforms. In that 791 * case, the platform uses phys_initrd_start/phys_initrd_size instead 792 * and does the VA conversion itself. 793 */ 794 if (!IS_ENABLED(CONFIG_ARM64) && 795 !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) { 796 initrd_start = (unsigned long)__va(start); 797 initrd_end = (unsigned long)__va(end); 798 initrd_below_start_ok = 1; 799 } 800 } 801 802 /** 803 * early_init_dt_check_for_initrd - Decode initrd location from flat tree 804 * @node: reference to node containing initrd location ('chosen') 805 */ 806 static void __init early_init_dt_check_for_initrd(unsigned long node) 807 { 808 u64 start, end; 809 int len; 810 const __be32 *prop; 811 812 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD)) 813 return; 814 815 pr_debug("Looking for initrd properties... "); 816 817 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len); 818 if (!prop) 819 return; 820 start = of_read_number(prop, len/4); 821 822 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len); 823 if (!prop) 824 return; 825 end = of_read_number(prop, len/4); 826 if (start > end) 827 return; 828 829 __early_init_dt_declare_initrd(start, end); 830 phys_initrd_start = start; 831 phys_initrd_size = end - start; 832 833 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end); 834 } 835 836 /** 837 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat 838 * tree 839 * @node: reference to node containing elfcorehdr location ('chosen') 840 */ 841 static void __init early_init_dt_check_for_elfcorehdr(unsigned long node) 842 { 843 if (!IS_ENABLED(CONFIG_CRASH_DUMP)) 844 return; 845 846 pr_debug("Looking for elfcorehdr property... "); 847 848 if (!of_flat_dt_get_addr_size(node, "linux,elfcorehdr", 849 &elfcorehdr_addr, &elfcorehdr_size)) 850 return; 851 852 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n", 853 elfcorehdr_addr, elfcorehdr_size); 854 } 855 856 static void __init early_init_dt_check_for_dmcryptkeys(unsigned long node) 857 { 858 const char *prop_name = "linux,dmcryptkeys"; 859 const __be32 *prop; 860 861 if (!IS_ENABLED(CONFIG_CRASH_DM_CRYPT)) 862 return; 863 864 pr_debug("Looking for dmcryptkeys property... "); 865 866 prop = of_get_flat_dt_prop(node, prop_name, NULL); 867 if (!prop) 868 return; 869 870 dm_crypt_keys_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); 871 872 /* Property only accessible to crash dump kernel */ 873 fdt_delprop(initial_boot_params, node, prop_name); 874 } 875 876 static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; 877 878 /* 879 * The main usage of linux,usable-memory-range is for crash dump kernel. 880 * Originally, the number of usable-memory regions is one. Now there may 881 * be two regions, low region and high region. 882 * To make compatibility with existing user-space and older kdump, the low 883 * region is always the last range of linux,usable-memory-range if exist. 884 */ 885 #define MAX_USABLE_RANGES 2 886 887 /** 888 * early_init_dt_check_for_usable_mem_range - Decode usable memory range 889 * location from flat tree 890 */ 891 void __init early_init_dt_check_for_usable_mem_range(void) 892 { 893 struct memblock_region rgn[MAX_USABLE_RANGES] = {0}; 894 const __be32 *prop; 895 int len, i; 896 u64 base, size; 897 unsigned long node = chosen_node_offset; 898 899 if ((long)node < 0) 900 return; 901 902 pr_debug("Looking for usable-memory-range property... "); 903 904 prop = of_flat_dt_get_addr_size_prop(node, "linux,usable-memory-range", 905 &len); 906 if (!prop) 907 return; 908 909 len = min(len, MAX_USABLE_RANGES); 910 911 for (i = 0; i < len; i++) { 912 of_flat_dt_read_addr_size(prop, i, &base, &size); 913 rgn[i].base = base; 914 rgn[i].size = size; 915 916 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n", 917 i, &rgn[i].base, &rgn[i].size); 918 } 919 920 memblock_cap_memory_range(rgn[0].base, rgn[0].size); 921 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++) 922 memblock_add(rgn[i].base, rgn[i].size); 923 } 924 925 /** 926 * early_init_dt_check_kho - Decode info required for kexec handover from DT 927 */ 928 static void __init early_init_dt_check_kho(void) 929 { 930 unsigned long node = chosen_node_offset; 931 u64 fdt_start, fdt_size, scratch_start, scratch_size; 932 933 if (!IS_ENABLED(CONFIG_KEXEC_HANDOVER) || (long)node < 0) 934 return; 935 936 if (!of_flat_dt_get_addr_size(node, "linux,kho-fdt", 937 &fdt_start, &fdt_size)) 938 return; 939 940 if (!of_flat_dt_get_addr_size(node, "linux,kho-scratch", 941 &scratch_start, &scratch_size)) 942 return; 943 944 kho_populate(fdt_start, fdt_size, scratch_start, scratch_size); 945 } 946 947 #ifdef CONFIG_SERIAL_EARLYCON 948 949 int __init early_init_dt_scan_chosen_stdout(void) 950 { 951 int offset; 952 const char *p, *q, *options = NULL; 953 int l; 954 const struct earlycon_id *match; 955 const void *fdt = initial_boot_params; 956 int ret; 957 958 offset = fdt_path_offset(fdt, "/chosen"); 959 if (offset < 0) 960 offset = fdt_path_offset(fdt, "/chosen@0"); 961 if (offset < 0) 962 return -ENOENT; 963 964 p = fdt_stringlist_get(fdt, offset, "stdout-path", 0, &l); 965 if (!p) 966 p = fdt_stringlist_get(fdt, offset, "linux,stdout-path", 0, &l); 967 if (!p || !l) 968 return -ENOENT; 969 970 q = strchrnul(p, ':'); 971 if (*q != '\0') 972 options = q + 1; 973 l = q - p; 974 975 /* Get the node specified by stdout-path */ 976 offset = fdt_path_offset_namelen(fdt, p, l); 977 if (offset < 0) { 978 pr_warn("earlycon: stdout-path %.*s not found\n", l, p); 979 return 0; 980 } 981 982 for (match = __earlycon_table; match < __earlycon_table_end; match++) { 983 if (!match->compatible[0]) 984 continue; 985 986 if (fdt_node_check_compatible(fdt, offset, match->compatible)) 987 continue; 988 989 ret = of_setup_earlycon(match, offset, options); 990 if (!ret || ret == -EALREADY) 991 return 0; 992 } 993 return -ENODEV; 994 } 995 #endif 996 997 /* 998 * early_init_dt_scan_root - fetch the top level address and size cells 999 */ 1000 int __init early_init_dt_scan_root(void) 1001 { 1002 const __be32 *prop; 1003 const void *fdt = initial_boot_params; 1004 int node = fdt_path_offset(fdt, "/"); 1005 1006 if (node < 0) 1007 return -ENODEV; 1008 1009 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 1010 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 1011 1012 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 1013 if (!WARN(!prop, "No '#size-cells' in root node\n")) 1014 dt_root_size_cells = be32_to_cpup(prop); 1015 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells); 1016 1017 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 1018 if (!WARN(!prop, "No '#address-cells' in root node\n")) 1019 dt_root_addr_cells = be32_to_cpup(prop); 1020 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells); 1021 1022 return 0; 1023 } 1024 1025 u64 __init dt_mem_next_cell(int s, const __be32 **cellp) 1026 { 1027 const __be32 *p = *cellp; 1028 1029 *cellp = p + s; 1030 return of_read_number(p, s); 1031 } 1032 1033 /* 1034 * early_init_dt_scan_memory - Look for and parse memory nodes 1035 */ 1036 int __init early_init_dt_scan_memory(void) 1037 { 1038 int node, found_memory = 0; 1039 const void *fdt = initial_boot_params; 1040 1041 fdt_for_each_subnode(node, fdt, 0) { 1042 const char *type = fdt_stringlist_get(fdt, node, 1043 "device_type", 0, NULL); 1044 const __be32 *reg; 1045 int i, l; 1046 bool hotpluggable; 1047 1048 /* We are scanning "memory" nodes only */ 1049 if (type == NULL || strcmp(type, "memory") != 0) 1050 continue; 1051 1052 if (!of_fdt_device_is_available(fdt, node)) 1053 continue; 1054 1055 reg = of_flat_dt_get_addr_size_prop(node, "linux,usable-memory", &l); 1056 if (reg == NULL) 1057 reg = of_flat_dt_get_addr_size_prop(node, "reg", &l); 1058 if (reg == NULL) 1059 continue; 1060 1061 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL); 1062 1063 pr_debug("memory scan node %s, reg {addr,size} entries %d,\n", 1064 fdt_get_name(fdt, node, NULL), l); 1065 1066 for (i = 0; i < l; i++) { 1067 u64 base, size; 1068 1069 of_flat_dt_read_addr_size(reg, i, &base, &size); 1070 1071 if (size == 0) 1072 continue; 1073 pr_debug(" - %llx, %llx\n", base, size); 1074 1075 early_init_dt_add_memory_arch(base, size); 1076 1077 found_memory = 1; 1078 1079 if (!hotpluggable) 1080 continue; 1081 1082 if (memblock_mark_hotplug(base, size)) 1083 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n", 1084 base, base + size); 1085 } 1086 } 1087 return found_memory; 1088 } 1089 1090 int __init early_init_dt_scan_chosen(char *cmdline) 1091 { 1092 int l, node; 1093 const char *p; 1094 const void *rng_seed; 1095 const void *fdt = initial_boot_params; 1096 1097 node = fdt_path_offset(fdt, "/chosen"); 1098 if (node < 0) 1099 node = fdt_path_offset(fdt, "/chosen@0"); 1100 if (node < 0) 1101 /* Handle the cmdline config options even if no /chosen node */ 1102 goto handle_cmdline; 1103 1104 chosen_node_offset = node; 1105 1106 early_init_dt_check_for_initrd(node); 1107 early_init_dt_check_for_elfcorehdr(node); 1108 early_init_dt_check_for_dmcryptkeys(node); 1109 1110 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l); 1111 if (rng_seed && l > 0) { 1112 add_bootloader_randomness(rng_seed, l); 1113 1114 /* try to clear seed so it won't be found. */ 1115 fdt_nop_property(initial_boot_params, node, "rng-seed"); 1116 1117 /* update CRC check value */ 1118 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1119 fdt_totalsize(initial_boot_params)); 1120 } 1121 1122 /* Retrieve command line */ 1123 p = of_get_flat_dt_prop(node, "bootargs", &l); 1124 if (p != NULL && l > 0) 1125 strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE)); 1126 1127 handle_cmdline: 1128 /* 1129 * CONFIG_CMDLINE is meant to be a default in case nothing else 1130 * managed to set the command line, unless CONFIG_CMDLINE_FORCE 1131 * is set in which case we override whatever was found earlier. 1132 */ 1133 #ifdef CONFIG_CMDLINE 1134 #if defined(CONFIG_CMDLINE_EXTEND) 1135 strlcat(cmdline, " ", COMMAND_LINE_SIZE); 1136 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1137 #elif defined(CONFIG_CMDLINE_FORCE) 1138 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1139 #else 1140 /* No arguments from boot loader, use kernel's cmdl*/ 1141 if (!((char *)cmdline)[0]) 1142 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1143 #endif 1144 #endif /* CONFIG_CMDLINE */ 1145 1146 pr_debug("Command line is: %s\n", (char *)cmdline); 1147 1148 return 0; 1149 } 1150 1151 #ifndef MIN_MEMBLOCK_ADDR 1152 #define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET) 1153 #endif 1154 #ifndef MAX_MEMBLOCK_ADDR 1155 #define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0) 1156 #endif 1157 1158 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) 1159 { 1160 const u64 phys_offset = MIN_MEMBLOCK_ADDR; 1161 1162 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { 1163 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1164 base, base + size); 1165 return; 1166 } 1167 1168 if (!PAGE_ALIGNED(base)) { 1169 size -= PAGE_SIZE - (base & ~PAGE_MASK); 1170 base = PAGE_ALIGN(base); 1171 } 1172 size &= PAGE_MASK; 1173 1174 if (base > MAX_MEMBLOCK_ADDR) { 1175 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1176 base, base + size); 1177 return; 1178 } 1179 1180 if (base + size - 1 > MAX_MEMBLOCK_ADDR) { 1181 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", 1182 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size); 1183 size = MAX_MEMBLOCK_ADDR - base + 1; 1184 } 1185 1186 if (base + size < phys_offset) { 1187 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1188 base, base + size); 1189 return; 1190 } 1191 if (base < phys_offset) { 1192 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", 1193 base, phys_offset); 1194 size -= phys_offset - base; 1195 base = phys_offset; 1196 } 1197 memblock_add(base, size); 1198 } 1199 1200 static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align) 1201 { 1202 return memblock_alloc_or_panic(size, align); 1203 } 1204 1205 bool __init early_init_dt_verify(void *dt_virt, phys_addr_t dt_phys) 1206 { 1207 if (!dt_virt) 1208 return false; 1209 1210 /* check device tree validity */ 1211 if (fdt_check_header(dt_virt)) 1212 return false; 1213 1214 /* Setup flat device-tree pointer */ 1215 initial_boot_params = dt_virt; 1216 initial_boot_params_pa = dt_phys; 1217 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1218 fdt_totalsize(initial_boot_params)); 1219 1220 /* Initialize {size,address}-cells info */ 1221 early_init_dt_scan_root(); 1222 1223 return true; 1224 } 1225 1226 1227 void __init early_init_dt_scan_nodes(void) 1228 { 1229 int rc; 1230 1231 /* Retrieve various information from the /chosen node */ 1232 rc = early_init_dt_scan_chosen(boot_command_line); 1233 if (rc) 1234 pr_warn("No chosen node found, continuing without\n"); 1235 1236 /* Setup memory, calling early_init_dt_add_memory_arch */ 1237 early_init_dt_scan_memory(); 1238 1239 /* Handle linux,usable-memory-range property */ 1240 early_init_dt_check_for_usable_mem_range(); 1241 1242 /* Handle kexec handover */ 1243 early_init_dt_check_kho(); 1244 } 1245 1246 bool __init early_init_dt_scan(void *dt_virt, phys_addr_t dt_phys) 1247 { 1248 bool status; 1249 1250 status = early_init_dt_verify(dt_virt, dt_phys); 1251 if (!status) 1252 return false; 1253 1254 early_init_dt_scan_nodes(); 1255 return true; 1256 } 1257 1258 static void *__init copy_device_tree(void *fdt) 1259 { 1260 int size; 1261 void *dt; 1262 1263 size = fdt_totalsize(fdt); 1264 dt = early_init_dt_alloc_memory_arch(size, 1265 roundup_pow_of_two(FDT_V17_SIZE)); 1266 1267 if (dt) 1268 memcpy(dt, fdt, size); 1269 1270 return dt; 1271 } 1272 1273 /** 1274 * unflatten_device_tree - create tree of device_nodes from flat blob 1275 * 1276 * unflattens the device-tree passed by the firmware, creating the 1277 * tree of struct device_node. It also fills the "name" and "type" 1278 * pointers of the nodes so the normal device-tree walking functions 1279 * can be used. 1280 */ 1281 void __init unflatten_device_tree(void) 1282 { 1283 void *fdt = initial_boot_params; 1284 1285 /* Save the statically-placed regions in the reserved_mem array */ 1286 fdt_scan_reserved_mem_late(); 1287 1288 /* Populate an empty root node when bootloader doesn't provide one */ 1289 if (!fdt) { 1290 fdt = (void *) __dtb_empty_root_begin; 1291 /* fdt_totalsize() will be used for copy size */ 1292 if (fdt_totalsize(fdt) > 1293 __dtb_empty_root_end - __dtb_empty_root_begin) { 1294 pr_err("invalid size in dtb_empty_root\n"); 1295 return; 1296 } 1297 of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt)); 1298 fdt = copy_device_tree(fdt); 1299 } 1300 1301 __unflatten_device_tree(fdt, NULL, &of_root, 1302 early_init_dt_alloc_memory_arch, false); 1303 1304 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ 1305 of_alias_scan(early_init_dt_alloc_memory_arch); 1306 1307 unittest_unflatten_overlay_base(); 1308 } 1309 1310 /** 1311 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob 1312 * 1313 * Copies and unflattens the device-tree passed by the firmware, creating the 1314 * tree of struct device_node. It also fills the "name" and "type" 1315 * pointers of the nodes so the normal device-tree walking functions 1316 * can be used. This should only be used when the FDT memory has not been 1317 * reserved such is the case when the FDT is built-in to the kernel init 1318 * section. If the FDT memory is reserved already then unflatten_device_tree 1319 * should be used instead. 1320 */ 1321 void __init unflatten_and_copy_device_tree(void) 1322 { 1323 if (initial_boot_params) 1324 initial_boot_params = copy_device_tree(initial_boot_params); 1325 1326 unflatten_device_tree(); 1327 } 1328 1329 #ifdef CONFIG_SYSFS 1330 static int __init of_fdt_raw_init(void) 1331 { 1332 static __ro_after_init BIN_ATTR_SIMPLE_ADMIN_RO(fdt); 1333 1334 if (!initial_boot_params) 1335 return 0; 1336 1337 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params, 1338 fdt_totalsize(initial_boot_params))) { 1339 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n"); 1340 return 0; 1341 } 1342 bin_attr_fdt.private = initial_boot_params; 1343 bin_attr_fdt.size = fdt_totalsize(initial_boot_params); 1344 return sysfs_create_bin_file(firmware_kobj, &bin_attr_fdt); 1345 } 1346 late_initcall(of_fdt_raw_init); 1347 #endif 1348 1349 #endif /* CONFIG_OF_EARLY_FLATTREE */ 1350