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/of_reserved_mem.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 #include <linux/kmemleak.h> 30 31 #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ 32 #include <asm/page.h> 33 34 #include "of_private.h" 35 36 /* 37 * of_fdt_limit_memory - limit the number of regions in the /memory node 38 * @limit: maximum entries 39 * 40 * Adjust the flattened device tree to have at most 'limit' number of 41 * memory entries in the /memory node. This function may be called 42 * any time after initial_boot_param is set. 43 */ 44 void __init of_fdt_limit_memory(int limit) 45 { 46 int memory; 47 int len; 48 const void *val; 49 int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 50 int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 51 const __be32 *addr_prop; 52 const __be32 *size_prop; 53 int root_offset; 54 int cell_size; 55 56 root_offset = fdt_path_offset(initial_boot_params, "/"); 57 if (root_offset < 0) 58 return; 59 60 addr_prop = fdt_getprop(initial_boot_params, root_offset, 61 "#address-cells", NULL); 62 if (addr_prop) 63 nr_address_cells = fdt32_to_cpu(*addr_prop); 64 65 size_prop = fdt_getprop(initial_boot_params, root_offset, 66 "#size-cells", NULL); 67 if (size_prop) 68 nr_size_cells = fdt32_to_cpu(*size_prop); 69 70 cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells); 71 72 memory = fdt_path_offset(initial_boot_params, "/memory"); 73 if (memory > 0) { 74 val = fdt_getprop(initial_boot_params, memory, "reg", &len); 75 if (len > limit*cell_size) { 76 len = limit*cell_size; 77 pr_debug("Limiting number of entries to %d\n", limit); 78 fdt_setprop(initial_boot_params, memory, "reg", val, 79 len); 80 } 81 } 82 } 83 84 static bool of_fdt_device_is_available(const void *blob, unsigned long node) 85 { 86 const char *status = fdt_getprop(blob, node, "status", NULL); 87 88 if (!status) 89 return true; 90 91 if (!strcmp(status, "ok") || !strcmp(status, "okay")) 92 return true; 93 94 return false; 95 } 96 97 static void *unflatten_dt_alloc(void **mem, unsigned long size, 98 unsigned long align) 99 { 100 void *res; 101 102 *mem = PTR_ALIGN(*mem, align); 103 res = *mem; 104 *mem += size; 105 106 return res; 107 } 108 109 static void populate_properties(const void *blob, 110 int offset, 111 void **mem, 112 struct device_node *np, 113 const char *nodename, 114 bool dryrun) 115 { 116 struct property *pp, **pprev = NULL; 117 int cur; 118 bool has_name = false; 119 120 pprev = &np->properties; 121 for (cur = fdt_first_property_offset(blob, offset); 122 cur >= 0; 123 cur = fdt_next_property_offset(blob, cur)) { 124 const __be32 *val; 125 const char *pname; 126 u32 sz; 127 128 val = fdt_getprop_by_offset(blob, cur, &pname, &sz); 129 if (!val) { 130 pr_warn("Cannot locate property at 0x%x\n", cur); 131 continue; 132 } 133 134 if (!pname) { 135 pr_warn("Cannot find property name at 0x%x\n", cur); 136 continue; 137 } 138 139 if (!strcmp(pname, "name")) 140 has_name = true; 141 142 pp = unflatten_dt_alloc(mem, sizeof(struct property), 143 __alignof__(struct property)); 144 if (dryrun) 145 continue; 146 147 /* We accept flattened tree phandles either in 148 * ePAPR-style "phandle" properties, or the 149 * legacy "linux,phandle" properties. If both 150 * appear and have different values, things 151 * will get weird. Don't do that. 152 */ 153 if (!strcmp(pname, "phandle") || 154 !strcmp(pname, "linux,phandle")) { 155 if (!np->phandle) 156 np->phandle = be32_to_cpup(val); 157 } 158 159 /* And we process the "ibm,phandle" property 160 * used in pSeries dynamic device tree 161 * stuff 162 */ 163 if (!strcmp(pname, "ibm,phandle")) 164 np->phandle = be32_to_cpup(val); 165 166 pp->name = (char *)pname; 167 pp->length = sz; 168 pp->value = (__be32 *)val; 169 *pprev = pp; 170 pprev = &pp->next; 171 } 172 173 /* With version 0x10 we may not have the name property, 174 * recreate it here from the unit name if absent 175 */ 176 if (!has_name) { 177 const char *p = nodename, *ps = p, *pa = NULL; 178 int len; 179 180 while (*p) { 181 if ((*p) == '@') 182 pa = p; 183 else if ((*p) == '/') 184 ps = p + 1; 185 p++; 186 } 187 188 if (pa < ps) 189 pa = p; 190 len = (pa - ps) + 1; 191 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len, 192 __alignof__(struct property)); 193 if (!dryrun) { 194 pp->name = "name"; 195 pp->length = len; 196 pp->value = pp + 1; 197 *pprev = pp; 198 memcpy(pp->value, ps, len - 1); 199 ((char *)pp->value)[len - 1] = 0; 200 pr_debug("fixed up name for %s -> %s\n", 201 nodename, (char *)pp->value); 202 } 203 } 204 } 205 206 static int populate_node(const void *blob, 207 int offset, 208 void **mem, 209 struct device_node *dad, 210 struct device_node **pnp, 211 bool dryrun) 212 { 213 struct device_node *np; 214 const char *pathp; 215 int len; 216 217 pathp = fdt_get_name(blob, offset, &len); 218 if (!pathp) { 219 *pnp = NULL; 220 return len; 221 } 222 223 len++; 224 225 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len, 226 __alignof__(struct device_node)); 227 if (!dryrun) { 228 char *fn; 229 of_node_init(np); 230 np->full_name = fn = ((char *)np) + sizeof(*np); 231 232 memcpy(fn, pathp, len); 233 234 if (dad != NULL) { 235 np->parent = dad; 236 np->sibling = dad->child; 237 dad->child = np; 238 } 239 } 240 241 populate_properties(blob, offset, mem, np, pathp, dryrun); 242 if (!dryrun) { 243 np->name = of_get_property(np, "name", NULL); 244 if (!np->name) 245 np->name = "<NULL>"; 246 } 247 248 *pnp = np; 249 return 0; 250 } 251 252 static void reverse_nodes(struct device_node *parent) 253 { 254 struct device_node *child, *next; 255 256 /* In-depth first */ 257 child = parent->child; 258 while (child) { 259 reverse_nodes(child); 260 261 child = child->sibling; 262 } 263 264 /* Reverse the nodes in the child list */ 265 child = parent->child; 266 parent->child = NULL; 267 while (child) { 268 next = child->sibling; 269 270 child->sibling = parent->child; 271 parent->child = child; 272 child = next; 273 } 274 } 275 276 /** 277 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree 278 * @blob: The parent device tree blob 279 * @mem: Memory chunk to use for allocating device nodes and properties 280 * @dad: Parent struct device_node 281 * @nodepp: The device_node tree created by the call 282 * 283 * Return: The size of unflattened device tree or error code 284 */ 285 static int unflatten_dt_nodes(const void *blob, 286 void *mem, 287 struct device_node *dad, 288 struct device_node **nodepp) 289 { 290 struct device_node *root; 291 int offset = 0, depth = 0, initial_depth = 0; 292 #define FDT_MAX_DEPTH 64 293 struct device_node *nps[FDT_MAX_DEPTH]; 294 void *base = mem; 295 bool dryrun = !base; 296 int ret; 297 298 if (nodepp) 299 *nodepp = NULL; 300 301 /* 302 * We're unflattening device sub-tree if @dad is valid. There are 303 * possibly multiple nodes in the first level of depth. We need 304 * set @depth to 1 to make fdt_next_node() happy as it bails 305 * immediately when negative @depth is found. Otherwise, the device 306 * nodes except the first one won't be unflattened successfully. 307 */ 308 if (dad) 309 depth = initial_depth = 1; 310 311 root = dad; 312 nps[depth] = dad; 313 314 for (offset = 0; 315 offset >= 0 && depth >= initial_depth; 316 offset = fdt_next_node(blob, offset, &depth)) { 317 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH)) 318 continue; 319 320 if (!IS_ENABLED(CONFIG_OF_KOBJ) && 321 !of_fdt_device_is_available(blob, offset)) 322 continue; 323 324 ret = populate_node(blob, offset, &mem, nps[depth], 325 &nps[depth+1], dryrun); 326 if (ret < 0) 327 return ret; 328 329 if (!dryrun && nodepp && !*nodepp) 330 *nodepp = nps[depth+1]; 331 if (!dryrun && !root) 332 root = nps[depth+1]; 333 } 334 335 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) { 336 pr_err("Error %d processing FDT\n", offset); 337 return -EINVAL; 338 } 339 340 /* 341 * Reverse the child list. Some drivers assumes node order matches .dts 342 * node order 343 */ 344 if (!dryrun) 345 reverse_nodes(root); 346 347 return mem - base; 348 } 349 350 /** 351 * __unflatten_device_tree - create tree of device_nodes from flat blob 352 * @blob: The blob to expand 353 * @dad: Parent device node 354 * @mynodes: The device_node tree created by the call 355 * @dt_alloc: An allocator that provides a virtual address to memory 356 * for the resulting tree 357 * @detached: if true set OF_DETACHED on @mynodes 358 * 359 * unflattens a device-tree, creating the tree of struct device_node. It also 360 * fills the "name" and "type" pointers of the nodes so the normal device-tree 361 * walking functions can be used. 362 * 363 * Return: NULL on failure or the memory chunk containing the unflattened 364 * device tree on success. 365 */ 366 void *__unflatten_device_tree(const void *blob, 367 struct device_node *dad, 368 struct device_node **mynodes, 369 void *(*dt_alloc)(u64 size, u64 align), 370 bool detached) 371 { 372 int size; 373 void *mem; 374 int ret; 375 376 if (mynodes) 377 *mynodes = NULL; 378 379 pr_debug(" -> unflatten_device_tree()\n"); 380 381 if (!blob) { 382 pr_debug("No device tree pointer\n"); 383 return NULL; 384 } 385 386 pr_debug("Unflattening device tree:\n"); 387 pr_debug("magic: %08x\n", fdt_magic(blob)); 388 pr_debug("size: %08x\n", fdt_totalsize(blob)); 389 pr_debug("version: %08x\n", fdt_version(blob)); 390 391 if (fdt_check_header(blob)) { 392 pr_err("Invalid device tree blob header\n"); 393 return NULL; 394 } 395 396 /* First pass, scan for size */ 397 size = unflatten_dt_nodes(blob, NULL, dad, NULL); 398 if (size <= 0) 399 return NULL; 400 401 size = ALIGN(size, 4); 402 pr_debug(" size is %d, allocating...\n", size); 403 404 /* Allocate memory for the expanded device tree */ 405 mem = dt_alloc(size + 4, __alignof__(struct device_node)); 406 if (!mem) 407 return NULL; 408 409 memset(mem, 0, size); 410 411 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef); 412 413 pr_debug(" unflattening %p...\n", mem); 414 415 /* Second pass, do actual unflattening */ 416 ret = unflatten_dt_nodes(blob, mem, dad, mynodes); 417 418 if (be32_to_cpup(mem + size) != 0xdeadbeef) 419 pr_warn("End of tree marker overwritten: %08x\n", 420 be32_to_cpup(mem + size)); 421 422 if (ret <= 0) 423 return NULL; 424 425 if (detached && mynodes && *mynodes) { 426 of_node_set_flag(*mynodes, OF_DETACHED); 427 pr_debug("unflattened tree is detached\n"); 428 } 429 430 pr_debug(" <- unflatten_device_tree()\n"); 431 return mem; 432 } 433 434 static void *kernel_tree_alloc(u64 size, u64 align) 435 { 436 return kzalloc(size, GFP_KERNEL); 437 } 438 439 static DEFINE_MUTEX(of_fdt_unflatten_mutex); 440 441 /** 442 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob 443 * @blob: Flat device tree blob 444 * @dad: Parent device node 445 * @mynodes: The device tree created by the call 446 * 447 * unflattens the device-tree passed by the firmware, creating the 448 * tree of struct device_node. It also fills the "name" and "type" 449 * pointers of the nodes so the normal device-tree walking functions 450 * can be used. 451 * 452 * Return: NULL on failure or the memory chunk containing the unflattened 453 * device tree on success. 454 */ 455 void *of_fdt_unflatten_tree(const unsigned long *blob, 456 struct device_node *dad, 457 struct device_node **mynodes) 458 { 459 void *mem; 460 461 mutex_lock(&of_fdt_unflatten_mutex); 462 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc, 463 true); 464 mutex_unlock(&of_fdt_unflatten_mutex); 465 466 return mem; 467 } 468 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree); 469 470 /* Everything below here references initial_boot_params directly. */ 471 int __initdata dt_root_addr_cells; 472 int __initdata dt_root_size_cells; 473 474 void *initial_boot_params __ro_after_init; 475 476 #ifdef CONFIG_OF_EARLY_FLATTREE 477 478 static u32 of_fdt_crc32; 479 480 static int __init early_init_dt_reserve_memory(phys_addr_t base, 481 phys_addr_t size, bool nomap) 482 { 483 if (nomap) { 484 /* 485 * If the memory is already reserved (by another region), we 486 * should not allow it to be marked nomap, but don't worry 487 * if the region isn't memory as it won't be mapped. 488 */ 489 if (memblock_overlaps_region(&memblock.memory, base, size) && 490 memblock_is_region_reserved(base, size)) 491 return -EBUSY; 492 493 return memblock_mark_nomap(base, size); 494 } 495 return memblock_reserve(base, size); 496 } 497 498 /* 499 * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property 500 */ 501 static int __init __reserved_mem_reserve_reg(unsigned long node, 502 const char *uname) 503 { 504 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32); 505 phys_addr_t base, size; 506 int len; 507 const __be32 *prop; 508 int first = 1; 509 bool nomap; 510 511 prop = of_get_flat_dt_prop(node, "reg", &len); 512 if (!prop) 513 return -ENOENT; 514 515 if (len && len % t_len != 0) { 516 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n", 517 uname); 518 return -EINVAL; 519 } 520 521 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL; 522 523 while (len >= t_len) { 524 base = dt_mem_next_cell(dt_root_addr_cells, &prop); 525 size = dt_mem_next_cell(dt_root_size_cells, &prop); 526 527 if (size && 528 early_init_dt_reserve_memory(base, size, nomap) == 0) { 529 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n", 530 uname, &base, (unsigned long)(size / SZ_1M)); 531 if (!nomap) 532 kmemleak_alloc_phys(base, size, 0); 533 } 534 else 535 pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n", 536 uname, &base, (unsigned long)(size / SZ_1M)); 537 538 len -= t_len; 539 if (first) { 540 fdt_reserved_mem_save_node(node, uname, base, size); 541 first = 0; 542 } 543 } 544 return 0; 545 } 546 547 /* 548 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided 549 * in /reserved-memory matches the values supported by the current implementation, 550 * also check if ranges property has been provided 551 */ 552 static int __init __reserved_mem_check_root(unsigned long node) 553 { 554 const __be32 *prop; 555 556 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 557 if (!prop || be32_to_cpup(prop) != dt_root_size_cells) 558 return -EINVAL; 559 560 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 561 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells) 562 return -EINVAL; 563 564 prop = of_get_flat_dt_prop(node, "ranges", NULL); 565 if (!prop) 566 return -EINVAL; 567 return 0; 568 } 569 570 /* 571 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory 572 */ 573 static int __init fdt_scan_reserved_mem(void) 574 { 575 int node, child; 576 const void *fdt = initial_boot_params; 577 578 node = fdt_path_offset(fdt, "/reserved-memory"); 579 if (node < 0) 580 return -ENODEV; 581 582 if (__reserved_mem_check_root(node) != 0) { 583 pr_err("Reserved memory: unsupported node format, ignoring\n"); 584 return -EINVAL; 585 } 586 587 fdt_for_each_subnode(child, fdt, node) { 588 const char *uname; 589 int err; 590 591 if (!of_fdt_device_is_available(fdt, child)) 592 continue; 593 594 uname = fdt_get_name(fdt, child, NULL); 595 596 err = __reserved_mem_reserve_reg(child, uname); 597 if (err == -ENOENT && of_get_flat_dt_prop(child, "size", NULL)) 598 fdt_reserved_mem_save_node(child, uname, 0, 0); 599 } 600 return 0; 601 } 602 603 /* 604 * fdt_reserve_elfcorehdr() - reserves memory for elf core header 605 * 606 * This function reserves the memory occupied by an elf core header 607 * described in the device tree. This region contains all the 608 * information about primary kernel's core image and is used by a dump 609 * capture kernel to access the system memory on primary kernel. 610 */ 611 static void __init fdt_reserve_elfcorehdr(void) 612 { 613 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size) 614 return; 615 616 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) { 617 pr_warn("elfcorehdr is overlapped\n"); 618 return; 619 } 620 621 memblock_reserve(elfcorehdr_addr, elfcorehdr_size); 622 623 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n", 624 elfcorehdr_size >> 10, elfcorehdr_addr); 625 } 626 627 /** 628 * early_init_fdt_scan_reserved_mem() - create reserved memory regions 629 * 630 * This function grabs memory from early allocator for device exclusive use 631 * defined in device tree structures. It should be called by arch specific code 632 * once the early allocator (i.e. memblock) has been fully activated. 633 */ 634 void __init early_init_fdt_scan_reserved_mem(void) 635 { 636 int n; 637 u64 base, size; 638 639 if (!initial_boot_params) 640 return; 641 642 /* Process header /memreserve/ fields */ 643 for (n = 0; ; n++) { 644 fdt_get_mem_rsv(initial_boot_params, n, &base, &size); 645 if (!size) 646 break; 647 memblock_reserve(base, size); 648 } 649 650 fdt_scan_reserved_mem(); 651 fdt_reserve_elfcorehdr(); 652 fdt_init_reserved_mem(); 653 } 654 655 /** 656 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob 657 */ 658 void __init early_init_fdt_reserve_self(void) 659 { 660 if (!initial_boot_params) 661 return; 662 663 /* Reserve the dtb region */ 664 memblock_reserve(__pa(initial_boot_params), 665 fdt_totalsize(initial_boot_params)); 666 } 667 668 /** 669 * of_scan_flat_dt - scan flattened tree blob and call callback on each. 670 * @it: callback function 671 * @data: context data pointer 672 * 673 * This function is used to scan the flattened device-tree, it is 674 * used to extract the memory information at boot before we can 675 * unflatten the tree 676 */ 677 int __init of_scan_flat_dt(int (*it)(unsigned long node, 678 const char *uname, int depth, 679 void *data), 680 void *data) 681 { 682 const void *blob = initial_boot_params; 683 const char *pathp; 684 int offset, rc = 0, depth = -1; 685 686 if (!blob) 687 return 0; 688 689 for (offset = fdt_next_node(blob, -1, &depth); 690 offset >= 0 && depth >= 0 && !rc; 691 offset = fdt_next_node(blob, offset, &depth)) { 692 693 pathp = fdt_get_name(blob, offset, NULL); 694 rc = it(offset, pathp, depth, data); 695 } 696 return rc; 697 } 698 699 /** 700 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each. 701 * @parent: parent node 702 * @it: callback function 703 * @data: context data pointer 704 * 705 * This function is used to scan sub-nodes of a node. 706 */ 707 int __init of_scan_flat_dt_subnodes(unsigned long parent, 708 int (*it)(unsigned long node, 709 const char *uname, 710 void *data), 711 void *data) 712 { 713 const void *blob = initial_boot_params; 714 int node; 715 716 fdt_for_each_subnode(node, blob, parent) { 717 const char *pathp; 718 int rc; 719 720 pathp = fdt_get_name(blob, node, NULL); 721 rc = it(node, pathp, data); 722 if (rc) 723 return rc; 724 } 725 return 0; 726 } 727 728 /** 729 * of_get_flat_dt_subnode_by_name - get the subnode by given name 730 * 731 * @node: the parent node 732 * @uname: the name of subnode 733 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none 734 */ 735 736 int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) 737 { 738 return fdt_subnode_offset(initial_boot_params, node, uname); 739 } 740 741 /* 742 * of_get_flat_dt_root - find the root node in the flat blob 743 */ 744 unsigned long __init of_get_flat_dt_root(void) 745 { 746 return 0; 747 } 748 749 /* 750 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr 751 * 752 * This function can be used within scan_flattened_dt callback to get 753 * access to properties 754 */ 755 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name, 756 int *size) 757 { 758 return fdt_getprop(initial_boot_params, node, name, size); 759 } 760 761 /** 762 * of_fdt_is_compatible - Return true if given node from the given blob has 763 * compat in its compatible list 764 * @blob: A device tree blob 765 * @node: node to test 766 * @compat: compatible string to compare with compatible list. 767 * 768 * Return: a non-zero value on match with smaller values returned for more 769 * specific compatible values. 770 */ 771 static int of_fdt_is_compatible(const void *blob, 772 unsigned long node, const char *compat) 773 { 774 const char *cp; 775 int cplen; 776 unsigned long l, score = 0; 777 778 cp = fdt_getprop(blob, node, "compatible", &cplen); 779 if (cp == NULL) 780 return 0; 781 while (cplen > 0) { 782 score++; 783 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) 784 return score; 785 l = strlen(cp) + 1; 786 cp += l; 787 cplen -= l; 788 } 789 790 return 0; 791 } 792 793 /** 794 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list 795 * @node: node to test 796 * @compat: compatible string to compare with compatible list. 797 */ 798 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat) 799 { 800 return of_fdt_is_compatible(initial_boot_params, node, compat); 801 } 802 803 /* 804 * of_flat_dt_match - Return true if node matches a list of compatible values 805 */ 806 static int __init of_flat_dt_match(unsigned long node, const char *const *compat) 807 { 808 unsigned int tmp, score = 0; 809 810 if (!compat) 811 return 0; 812 813 while (*compat) { 814 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat); 815 if (tmp && (score == 0 || (tmp < score))) 816 score = tmp; 817 compat++; 818 } 819 820 return score; 821 } 822 823 /* 824 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle 825 */ 826 uint32_t __init of_get_flat_dt_phandle(unsigned long node) 827 { 828 return fdt_get_phandle(initial_boot_params, node); 829 } 830 831 struct fdt_scan_status { 832 const char *name; 833 int namelen; 834 int depth; 835 int found; 836 int (*iterator)(unsigned long node, const char *uname, int depth, void *data); 837 void *data; 838 }; 839 840 const char * __init of_flat_dt_get_machine_name(void) 841 { 842 const char *name; 843 unsigned long dt_root = of_get_flat_dt_root(); 844 845 name = of_get_flat_dt_prop(dt_root, "model", NULL); 846 if (!name) 847 name = of_get_flat_dt_prop(dt_root, "compatible", NULL); 848 return name; 849 } 850 851 /** 852 * of_flat_dt_match_machine - Iterate match tables to find matching machine. 853 * 854 * @default_match: A machine specific ptr to return in case of no match. 855 * @get_next_compat: callback function to return next compatible match table. 856 * 857 * Iterate through machine match tables to find the best match for the machine 858 * compatible string in the FDT. 859 */ 860 const void * __init of_flat_dt_match_machine(const void *default_match, 861 const void * (*get_next_compat)(const char * const**)) 862 { 863 const void *data = NULL; 864 const void *best_data = default_match; 865 const char *const *compat; 866 unsigned long dt_root; 867 unsigned int best_score = ~1, score = 0; 868 869 dt_root = of_get_flat_dt_root(); 870 while ((data = get_next_compat(&compat))) { 871 score = of_flat_dt_match(dt_root, compat); 872 if (score > 0 && score < best_score) { 873 best_data = data; 874 best_score = score; 875 } 876 } 877 if (!best_data) { 878 const char *prop; 879 int size; 880 881 pr_err("\n unrecognized device tree list:\n[ "); 882 883 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 884 if (prop) { 885 while (size > 0) { 886 printk("'%s' ", prop); 887 size -= strlen(prop) + 1; 888 prop += strlen(prop) + 1; 889 } 890 } 891 printk("]\n\n"); 892 return NULL; 893 } 894 895 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name()); 896 897 return best_data; 898 } 899 900 static void __early_init_dt_declare_initrd(unsigned long start, 901 unsigned long end) 902 { 903 /* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is 904 * enabled since __va() is called too early. ARM64 does make use 905 * of phys_initrd_start/phys_initrd_size so we can skip this 906 * conversion. 907 */ 908 if (!IS_ENABLED(CONFIG_ARM64)) { 909 initrd_start = (unsigned long)__va(start); 910 initrd_end = (unsigned long)__va(end); 911 initrd_below_start_ok = 1; 912 } 913 } 914 915 /** 916 * early_init_dt_check_for_initrd - Decode initrd location from flat tree 917 * @node: reference to node containing initrd location ('chosen') 918 */ 919 static void __init early_init_dt_check_for_initrd(unsigned long node) 920 { 921 u64 start, end; 922 int len; 923 const __be32 *prop; 924 925 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD)) 926 return; 927 928 pr_debug("Looking for initrd properties... "); 929 930 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len); 931 if (!prop) 932 return; 933 start = of_read_number(prop, len/4); 934 935 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len); 936 if (!prop) 937 return; 938 end = of_read_number(prop, len/4); 939 940 __early_init_dt_declare_initrd(start, end); 941 phys_initrd_start = start; 942 phys_initrd_size = end - start; 943 944 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end); 945 } 946 947 /** 948 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat 949 * tree 950 * @node: reference to node containing elfcorehdr location ('chosen') 951 */ 952 static void __init early_init_dt_check_for_elfcorehdr(unsigned long node) 953 { 954 const __be32 *prop; 955 int len; 956 957 if (!IS_ENABLED(CONFIG_CRASH_DUMP)) 958 return; 959 960 pr_debug("Looking for elfcorehdr property... "); 961 962 prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len); 963 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells))) 964 return; 965 966 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); 967 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop); 968 969 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n", 970 elfcorehdr_addr, elfcorehdr_size); 971 } 972 973 static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; 974 975 /* 976 * The main usage of linux,usable-memory-range is for crash dump kernel. 977 * Originally, the number of usable-memory regions is one. Now there may 978 * be two regions, low region and high region. 979 * To make compatibility with existing user-space and older kdump, the low 980 * region is always the last range of linux,usable-memory-range if exist. 981 */ 982 #define MAX_USABLE_RANGES 2 983 984 /** 985 * early_init_dt_check_for_usable_mem_range - Decode usable memory range 986 * location from flat tree 987 */ 988 void __init early_init_dt_check_for_usable_mem_range(void) 989 { 990 struct memblock_region rgn[MAX_USABLE_RANGES] = {0}; 991 const __be32 *prop, *endp; 992 int len, i; 993 unsigned long node = chosen_node_offset; 994 995 if ((long)node < 0) 996 return; 997 998 pr_debug("Looking for usable-memory-range property... "); 999 1000 prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); 1001 if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells))) 1002 return; 1003 1004 endp = prop + (len / sizeof(__be32)); 1005 for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) { 1006 rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop); 1007 rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop); 1008 1009 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n", 1010 i, &rgn[i].base, &rgn[i].size); 1011 } 1012 1013 memblock_cap_memory_range(rgn[0].base, rgn[0].size); 1014 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++) 1015 memblock_add(rgn[i].base, rgn[i].size); 1016 } 1017 1018 #ifdef CONFIG_SERIAL_EARLYCON 1019 1020 int __init early_init_dt_scan_chosen_stdout(void) 1021 { 1022 int offset; 1023 const char *p, *q, *options = NULL; 1024 int l; 1025 const struct earlycon_id *match; 1026 const void *fdt = initial_boot_params; 1027 int ret; 1028 1029 offset = fdt_path_offset(fdt, "/chosen"); 1030 if (offset < 0) 1031 offset = fdt_path_offset(fdt, "/chosen@0"); 1032 if (offset < 0) 1033 return -ENOENT; 1034 1035 p = fdt_getprop(fdt, offset, "stdout-path", &l); 1036 if (!p) 1037 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l); 1038 if (!p || !l) 1039 return -ENOENT; 1040 1041 q = strchrnul(p, ':'); 1042 if (*q != '\0') 1043 options = q + 1; 1044 l = q - p; 1045 1046 /* Get the node specified by stdout-path */ 1047 offset = fdt_path_offset_namelen(fdt, p, l); 1048 if (offset < 0) { 1049 pr_warn("earlycon: stdout-path %.*s not found\n", l, p); 1050 return 0; 1051 } 1052 1053 for (match = __earlycon_table; match < __earlycon_table_end; match++) { 1054 if (!match->compatible[0]) 1055 continue; 1056 1057 if (fdt_node_check_compatible(fdt, offset, match->compatible)) 1058 continue; 1059 1060 ret = of_setup_earlycon(match, offset, options); 1061 if (!ret || ret == -EALREADY) 1062 return 0; 1063 } 1064 return -ENODEV; 1065 } 1066 #endif 1067 1068 /* 1069 * early_init_dt_scan_root - fetch the top level address and size cells 1070 */ 1071 int __init early_init_dt_scan_root(void) 1072 { 1073 const __be32 *prop; 1074 const void *fdt = initial_boot_params; 1075 int node = fdt_path_offset(fdt, "/"); 1076 1077 if (node < 0) 1078 return -ENODEV; 1079 1080 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 1081 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 1082 1083 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 1084 if (prop) 1085 dt_root_size_cells = be32_to_cpup(prop); 1086 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells); 1087 1088 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 1089 if (prop) 1090 dt_root_addr_cells = be32_to_cpup(prop); 1091 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells); 1092 1093 return 0; 1094 } 1095 1096 u64 __init dt_mem_next_cell(int s, const __be32 **cellp) 1097 { 1098 const __be32 *p = *cellp; 1099 1100 *cellp = p + s; 1101 return of_read_number(p, s); 1102 } 1103 1104 /* 1105 * early_init_dt_scan_memory - Look for and parse memory nodes 1106 */ 1107 int __init early_init_dt_scan_memory(void) 1108 { 1109 int node; 1110 const void *fdt = initial_boot_params; 1111 1112 fdt_for_each_subnode(node, fdt, 0) { 1113 const char *type = of_get_flat_dt_prop(node, "device_type", NULL); 1114 const __be32 *reg, *endp; 1115 int l; 1116 bool hotpluggable; 1117 1118 /* We are scanning "memory" nodes only */ 1119 if (type == NULL || strcmp(type, "memory") != 0) 1120 continue; 1121 1122 if (!of_fdt_device_is_available(fdt, node)) 1123 continue; 1124 1125 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l); 1126 if (reg == NULL) 1127 reg = of_get_flat_dt_prop(node, "reg", &l); 1128 if (reg == NULL) 1129 continue; 1130 1131 endp = reg + (l / sizeof(__be32)); 1132 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL); 1133 1134 pr_debug("memory scan node %s, reg size %d,\n", 1135 fdt_get_name(fdt, node, NULL), l); 1136 1137 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) { 1138 u64 base, size; 1139 1140 base = dt_mem_next_cell(dt_root_addr_cells, ®); 1141 size = dt_mem_next_cell(dt_root_size_cells, ®); 1142 1143 if (size == 0) 1144 continue; 1145 pr_debug(" - %llx, %llx\n", base, size); 1146 1147 early_init_dt_add_memory_arch(base, size); 1148 1149 if (!hotpluggable) 1150 continue; 1151 1152 if (memblock_mark_hotplug(base, size)) 1153 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n", 1154 base, base + size); 1155 } 1156 } 1157 return 0; 1158 } 1159 1160 int __init early_init_dt_scan_chosen(char *cmdline) 1161 { 1162 int l, node; 1163 const char *p; 1164 const void *rng_seed; 1165 const void *fdt = initial_boot_params; 1166 1167 node = fdt_path_offset(fdt, "/chosen"); 1168 if (node < 0) 1169 node = fdt_path_offset(fdt, "/chosen@0"); 1170 if (node < 0) 1171 return -ENOENT; 1172 1173 chosen_node_offset = node; 1174 1175 early_init_dt_check_for_initrd(node); 1176 early_init_dt_check_for_elfcorehdr(node); 1177 1178 /* Retrieve command line */ 1179 p = of_get_flat_dt_prop(node, "bootargs", &l); 1180 if (p != NULL && l > 0) 1181 strlcpy(cmdline, p, min(l, COMMAND_LINE_SIZE)); 1182 1183 /* 1184 * CONFIG_CMDLINE is meant to be a default in case nothing else 1185 * managed to set the command line, unless CONFIG_CMDLINE_FORCE 1186 * is set in which case we override whatever was found earlier. 1187 */ 1188 #ifdef CONFIG_CMDLINE 1189 #if defined(CONFIG_CMDLINE_EXTEND) 1190 strlcat(cmdline, " ", COMMAND_LINE_SIZE); 1191 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1192 #elif defined(CONFIG_CMDLINE_FORCE) 1193 strlcpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1194 #else 1195 /* No arguments from boot loader, use kernel's cmdl*/ 1196 if (!((char *)cmdline)[0]) 1197 strlcpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1198 #endif 1199 #endif /* CONFIG_CMDLINE */ 1200 1201 pr_debug("Command line is: %s\n", (char *)cmdline); 1202 1203 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l); 1204 if (rng_seed && l > 0) { 1205 add_bootloader_randomness(rng_seed, l); 1206 1207 /* try to clear seed so it won't be found. */ 1208 fdt_nop_property(initial_boot_params, node, "rng-seed"); 1209 1210 /* update CRC check value */ 1211 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1212 fdt_totalsize(initial_boot_params)); 1213 } 1214 1215 return 0; 1216 } 1217 1218 #ifndef MIN_MEMBLOCK_ADDR 1219 #define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET) 1220 #endif 1221 #ifndef MAX_MEMBLOCK_ADDR 1222 #define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0) 1223 #endif 1224 1225 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) 1226 { 1227 const u64 phys_offset = MIN_MEMBLOCK_ADDR; 1228 1229 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { 1230 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1231 base, base + size); 1232 return; 1233 } 1234 1235 if (!PAGE_ALIGNED(base)) { 1236 size -= PAGE_SIZE - (base & ~PAGE_MASK); 1237 base = PAGE_ALIGN(base); 1238 } 1239 size &= PAGE_MASK; 1240 1241 if (base > MAX_MEMBLOCK_ADDR) { 1242 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1243 base, base + size); 1244 return; 1245 } 1246 1247 if (base + size - 1 > MAX_MEMBLOCK_ADDR) { 1248 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", 1249 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size); 1250 size = MAX_MEMBLOCK_ADDR - base + 1; 1251 } 1252 1253 if (base + size < phys_offset) { 1254 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1255 base, base + size); 1256 return; 1257 } 1258 if (base < phys_offset) { 1259 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", 1260 base, phys_offset); 1261 size -= phys_offset - base; 1262 base = phys_offset; 1263 } 1264 memblock_add(base, size); 1265 } 1266 1267 static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align) 1268 { 1269 void *ptr = memblock_alloc(size, align); 1270 1271 if (!ptr) 1272 panic("%s: Failed to allocate %llu bytes align=0x%llx\n", 1273 __func__, size, align); 1274 1275 return ptr; 1276 } 1277 1278 bool __init early_init_dt_verify(void *params) 1279 { 1280 if (!params) 1281 return false; 1282 1283 /* check device tree validity */ 1284 if (fdt_check_header(params)) 1285 return false; 1286 1287 /* Setup flat device-tree pointer */ 1288 initial_boot_params = params; 1289 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1290 fdt_totalsize(initial_boot_params)); 1291 return true; 1292 } 1293 1294 1295 void __init early_init_dt_scan_nodes(void) 1296 { 1297 int rc; 1298 1299 /* Initialize {size,address}-cells info */ 1300 early_init_dt_scan_root(); 1301 1302 /* Retrieve various information from the /chosen node */ 1303 rc = early_init_dt_scan_chosen(boot_command_line); 1304 if (rc) 1305 pr_warn("No chosen node found, continuing without\n"); 1306 1307 /* Setup memory, calling early_init_dt_add_memory_arch */ 1308 early_init_dt_scan_memory(); 1309 1310 /* Handle linux,usable-memory-range property */ 1311 early_init_dt_check_for_usable_mem_range(); 1312 } 1313 1314 bool __init early_init_dt_scan(void *params) 1315 { 1316 bool status; 1317 1318 status = early_init_dt_verify(params); 1319 if (!status) 1320 return false; 1321 1322 early_init_dt_scan_nodes(); 1323 return true; 1324 } 1325 1326 /** 1327 * unflatten_device_tree - create tree of device_nodes from flat blob 1328 * 1329 * unflattens the device-tree passed by the firmware, creating the 1330 * tree of struct device_node. It also fills the "name" and "type" 1331 * pointers of the nodes so the normal device-tree walking functions 1332 * can be used. 1333 */ 1334 void __init unflatten_device_tree(void) 1335 { 1336 __unflatten_device_tree(initial_boot_params, NULL, &of_root, 1337 early_init_dt_alloc_memory_arch, false); 1338 1339 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ 1340 of_alias_scan(early_init_dt_alloc_memory_arch); 1341 1342 unittest_unflatten_overlay_base(); 1343 } 1344 1345 /** 1346 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob 1347 * 1348 * Copies and unflattens the device-tree passed by the firmware, creating the 1349 * tree of struct device_node. It also fills the "name" and "type" 1350 * pointers of the nodes so the normal device-tree walking functions 1351 * can be used. This should only be used when the FDT memory has not been 1352 * reserved such is the case when the FDT is built-in to the kernel init 1353 * section. If the FDT memory is reserved already then unflatten_device_tree 1354 * should be used instead. 1355 */ 1356 void __init unflatten_and_copy_device_tree(void) 1357 { 1358 int size; 1359 void *dt; 1360 1361 if (!initial_boot_params) { 1362 pr_warn("No valid device tree found, continuing without\n"); 1363 return; 1364 } 1365 1366 size = fdt_totalsize(initial_boot_params); 1367 dt = early_init_dt_alloc_memory_arch(size, 1368 roundup_pow_of_two(FDT_V17_SIZE)); 1369 1370 if (dt) { 1371 memcpy(dt, initial_boot_params, size); 1372 initial_boot_params = dt; 1373 } 1374 unflatten_device_tree(); 1375 } 1376 1377 #ifdef CONFIG_SYSFS 1378 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj, 1379 struct bin_attribute *bin_attr, 1380 char *buf, loff_t off, size_t count) 1381 { 1382 memcpy(buf, initial_boot_params + off, count); 1383 return count; 1384 } 1385 1386 static int __init of_fdt_raw_init(void) 1387 { 1388 static struct bin_attribute of_fdt_raw_attr = 1389 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0); 1390 1391 if (!initial_boot_params) 1392 return 0; 1393 1394 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params, 1395 fdt_totalsize(initial_boot_params))) { 1396 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n"); 1397 return 0; 1398 } 1399 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params); 1400 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr); 1401 } 1402 late_initcall(of_fdt_raw_init); 1403 #endif 1404 1405 #endif /* CONFIG_OF_EARLY_FLATTREE */ 1406