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 true; 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_arch(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_arch(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, 0); 533 } 534 else 535 pr_info("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 early_init_dt_reserve_memory_arch(base, size, false); 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 early_init_dt_reserve_memory_arch(__pa(initial_boot_params), 665 fdt_totalsize(initial_boot_params), 666 false); 667 } 668 669 /** 670 * of_scan_flat_dt - scan flattened tree blob and call callback on each. 671 * @it: callback function 672 * @data: context data pointer 673 * 674 * This function is used to scan the flattened device-tree, it is 675 * used to extract the memory information at boot before we can 676 * unflatten the tree 677 */ 678 int __init of_scan_flat_dt(int (*it)(unsigned long node, 679 const char *uname, int depth, 680 void *data), 681 void *data) 682 { 683 const void *blob = initial_boot_params; 684 const char *pathp; 685 int offset, rc = 0, depth = -1; 686 687 if (!blob) 688 return 0; 689 690 for (offset = fdt_next_node(blob, -1, &depth); 691 offset >= 0 && depth >= 0 && !rc; 692 offset = fdt_next_node(blob, offset, &depth)) { 693 694 pathp = fdt_get_name(blob, offset, NULL); 695 rc = it(offset, pathp, depth, data); 696 } 697 return rc; 698 } 699 700 /** 701 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each. 702 * @parent: parent node 703 * @it: callback function 704 * @data: context data pointer 705 * 706 * This function is used to scan sub-nodes of a node. 707 */ 708 int __init of_scan_flat_dt_subnodes(unsigned long parent, 709 int (*it)(unsigned long node, 710 const char *uname, 711 void *data), 712 void *data) 713 { 714 const void *blob = initial_boot_params; 715 int node; 716 717 fdt_for_each_subnode(node, blob, parent) { 718 const char *pathp; 719 int rc; 720 721 pathp = fdt_get_name(blob, node, NULL); 722 rc = it(node, pathp, data); 723 if (rc) 724 return rc; 725 } 726 return 0; 727 } 728 729 /** 730 * of_get_flat_dt_subnode_by_name - get the subnode by given name 731 * 732 * @node: the parent node 733 * @uname: the name of subnode 734 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none 735 */ 736 737 int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) 738 { 739 return fdt_subnode_offset(initial_boot_params, node, uname); 740 } 741 742 /* 743 * of_get_flat_dt_root - find the root node in the flat blob 744 */ 745 unsigned long __init of_get_flat_dt_root(void) 746 { 747 return 0; 748 } 749 750 /* 751 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr 752 * 753 * This function can be used within scan_flattened_dt callback to get 754 * access to properties 755 */ 756 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name, 757 int *size) 758 { 759 return fdt_getprop(initial_boot_params, node, name, size); 760 } 761 762 /** 763 * of_fdt_is_compatible - Return true if given node from the given blob has 764 * compat in its compatible list 765 * @blob: A device tree blob 766 * @node: node to test 767 * @compat: compatible string to compare with compatible list. 768 * 769 * Return: a non-zero value on match with smaller values returned for more 770 * specific compatible values. 771 */ 772 static int of_fdt_is_compatible(const void *blob, 773 unsigned long node, const char *compat) 774 { 775 const char *cp; 776 int cplen; 777 unsigned long l, score = 0; 778 779 cp = fdt_getprop(blob, node, "compatible", &cplen); 780 if (cp == NULL) 781 return 0; 782 while (cplen > 0) { 783 score++; 784 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) 785 return score; 786 l = strlen(cp) + 1; 787 cp += l; 788 cplen -= l; 789 } 790 791 return 0; 792 } 793 794 /** 795 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list 796 * @node: node to test 797 * @compat: compatible string to compare with compatible list. 798 */ 799 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat) 800 { 801 return of_fdt_is_compatible(initial_boot_params, node, compat); 802 } 803 804 /* 805 * of_flat_dt_match - Return true if node matches a list of compatible values 806 */ 807 static int __init of_flat_dt_match(unsigned long node, const char *const *compat) 808 { 809 unsigned int tmp, score = 0; 810 811 if (!compat) 812 return 0; 813 814 while (*compat) { 815 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat); 816 if (tmp && (score == 0 || (tmp < score))) 817 score = tmp; 818 compat++; 819 } 820 821 return score; 822 } 823 824 /* 825 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle 826 */ 827 uint32_t __init of_get_flat_dt_phandle(unsigned long node) 828 { 829 return fdt_get_phandle(initial_boot_params, node); 830 } 831 832 struct fdt_scan_status { 833 const char *name; 834 int namelen; 835 int depth; 836 int found; 837 int (*iterator)(unsigned long node, const char *uname, int depth, void *data); 838 void *data; 839 }; 840 841 const char * __init of_flat_dt_get_machine_name(void) 842 { 843 const char *name; 844 unsigned long dt_root = of_get_flat_dt_root(); 845 846 name = of_get_flat_dt_prop(dt_root, "model", NULL); 847 if (!name) 848 name = of_get_flat_dt_prop(dt_root, "compatible", NULL); 849 return name; 850 } 851 852 /** 853 * of_flat_dt_match_machine - Iterate match tables to find matching machine. 854 * 855 * @default_match: A machine specific ptr to return in case of no match. 856 * @get_next_compat: callback function to return next compatible match table. 857 * 858 * Iterate through machine match tables to find the best match for the machine 859 * compatible string in the FDT. 860 */ 861 const void * __init of_flat_dt_match_machine(const void *default_match, 862 const void * (*get_next_compat)(const char * const**)) 863 { 864 const void *data = NULL; 865 const void *best_data = default_match; 866 const char *const *compat; 867 unsigned long dt_root; 868 unsigned int best_score = ~1, score = 0; 869 870 dt_root = of_get_flat_dt_root(); 871 while ((data = get_next_compat(&compat))) { 872 score = of_flat_dt_match(dt_root, compat); 873 if (score > 0 && score < best_score) { 874 best_data = data; 875 best_score = score; 876 } 877 } 878 if (!best_data) { 879 const char *prop; 880 int size; 881 882 pr_err("\n unrecognized device tree list:\n[ "); 883 884 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 885 if (prop) { 886 while (size > 0) { 887 printk("'%s' ", prop); 888 size -= strlen(prop) + 1; 889 prop += strlen(prop) + 1; 890 } 891 } 892 printk("]\n\n"); 893 return NULL; 894 } 895 896 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name()); 897 898 return best_data; 899 } 900 901 static void __early_init_dt_declare_initrd(unsigned long start, 902 unsigned long end) 903 { 904 /* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is 905 * enabled since __va() is called too early. ARM64 does make use 906 * of phys_initrd_start/phys_initrd_size so we can skip this 907 * conversion. 908 */ 909 if (!IS_ENABLED(CONFIG_ARM64)) { 910 initrd_start = (unsigned long)__va(start); 911 initrd_end = (unsigned long)__va(end); 912 initrd_below_start_ok = 1; 913 } 914 } 915 916 /** 917 * early_init_dt_check_for_initrd - Decode initrd location from flat tree 918 * @node: reference to node containing initrd location ('chosen') 919 */ 920 static void __init early_init_dt_check_for_initrd(unsigned long node) 921 { 922 u64 start, end; 923 int len; 924 const __be32 *prop; 925 926 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD)) 927 return; 928 929 pr_debug("Looking for initrd properties... "); 930 931 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len); 932 if (!prop) 933 return; 934 start = of_read_number(prop, len/4); 935 936 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len); 937 if (!prop) 938 return; 939 end = of_read_number(prop, len/4); 940 941 __early_init_dt_declare_initrd(start, end); 942 phys_initrd_start = start; 943 phys_initrd_size = end - start; 944 945 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end); 946 } 947 948 /** 949 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat 950 * tree 951 * @node: reference to node containing elfcorehdr location ('chosen') 952 */ 953 static void __init early_init_dt_check_for_elfcorehdr(unsigned long node) 954 { 955 const __be32 *prop; 956 int len; 957 958 if (!IS_ENABLED(CONFIG_CRASH_DUMP)) 959 return; 960 961 pr_debug("Looking for elfcorehdr property... "); 962 963 prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len); 964 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells))) 965 return; 966 967 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); 968 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop); 969 970 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n", 971 elfcorehdr_addr, elfcorehdr_size); 972 } 973 974 static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; 975 976 /* 977 * The main usage of linux,usable-memory-range is for crash dump kernel. 978 * Originally, the number of usable-memory regions is one. Now there may 979 * be two regions, low region and high region. 980 * To make compatibility with existing user-space and older kdump, the low 981 * region is always the last range of linux,usable-memory-range if exist. 982 */ 983 #define MAX_USABLE_RANGES 2 984 985 /** 986 * early_init_dt_check_for_usable_mem_range - Decode usable memory range 987 * location from flat tree 988 */ 989 void __init early_init_dt_check_for_usable_mem_range(void) 990 { 991 struct memblock_region rgn[MAX_USABLE_RANGES] = {0}; 992 const __be32 *prop, *endp; 993 int len, i; 994 unsigned long node = chosen_node_offset; 995 996 if ((long)node < 0) 997 return; 998 999 pr_debug("Looking for usable-memory-range property... "); 1000 1001 prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); 1002 if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells))) 1003 return; 1004 1005 endp = prop + (len / sizeof(__be32)); 1006 for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) { 1007 rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop); 1008 rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop); 1009 1010 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n", 1011 i, &rgn[i].base, &rgn[i].size); 1012 } 1013 1014 memblock_cap_memory_range(rgn[0].base, rgn[0].size); 1015 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++) 1016 memblock_add(rgn[i].base, rgn[i].size); 1017 } 1018 1019 #ifdef CONFIG_SERIAL_EARLYCON 1020 1021 int __init early_init_dt_scan_chosen_stdout(void) 1022 { 1023 int offset; 1024 const char *p, *q, *options = NULL; 1025 int l; 1026 const struct earlycon_id *match; 1027 const void *fdt = initial_boot_params; 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 if (of_setup_earlycon(match, offset, options) == 0) 1061 return 0; 1062 } 1063 return -ENODEV; 1064 } 1065 #endif 1066 1067 /* 1068 * early_init_dt_scan_root - fetch the top level address and size cells 1069 */ 1070 int __init early_init_dt_scan_root(void) 1071 { 1072 const __be32 *prop; 1073 const void *fdt = initial_boot_params; 1074 int node = fdt_path_offset(fdt, "/"); 1075 1076 if (node < 0) 1077 return -ENODEV; 1078 1079 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 1080 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 1081 1082 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 1083 if (prop) 1084 dt_root_size_cells = be32_to_cpup(prop); 1085 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells); 1086 1087 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 1088 if (prop) 1089 dt_root_addr_cells = be32_to_cpup(prop); 1090 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells); 1091 1092 return 0; 1093 } 1094 1095 u64 __init dt_mem_next_cell(int s, const __be32 **cellp) 1096 { 1097 const __be32 *p = *cellp; 1098 1099 *cellp = p + s; 1100 return of_read_number(p, s); 1101 } 1102 1103 /* 1104 * early_init_dt_scan_memory - Look for and parse memory nodes 1105 */ 1106 int __init early_init_dt_scan_memory(void) 1107 { 1108 int node; 1109 const void *fdt = initial_boot_params; 1110 1111 fdt_for_each_subnode(node, fdt, 0) { 1112 const char *type = of_get_flat_dt_prop(node, "device_type", NULL); 1113 const __be32 *reg, *endp; 1114 int l; 1115 bool hotpluggable; 1116 1117 /* We are scanning "memory" nodes only */ 1118 if (type == NULL || strcmp(type, "memory") != 0) 1119 continue; 1120 1121 if (!of_fdt_device_is_available(fdt, node)) 1122 continue; 1123 1124 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l); 1125 if (reg == NULL) 1126 reg = of_get_flat_dt_prop(node, "reg", &l); 1127 if (reg == NULL) 1128 continue; 1129 1130 endp = reg + (l / sizeof(__be32)); 1131 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL); 1132 1133 pr_debug("memory scan node %s, reg size %d,\n", 1134 fdt_get_name(fdt, node, NULL), l); 1135 1136 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) { 1137 u64 base, size; 1138 1139 base = dt_mem_next_cell(dt_root_addr_cells, ®); 1140 size = dt_mem_next_cell(dt_root_size_cells, ®); 1141 1142 if (size == 0) 1143 continue; 1144 pr_debug(" - %llx, %llx\n", base, size); 1145 1146 early_init_dt_add_memory_arch(base, size); 1147 1148 if (!hotpluggable) 1149 continue; 1150 1151 if (memblock_mark_hotplug(base, size)) 1152 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n", 1153 base, base + size); 1154 } 1155 } 1156 return 0; 1157 } 1158 1159 int __init early_init_dt_scan_chosen(char *cmdline) 1160 { 1161 int l, node; 1162 const char *p; 1163 const void *rng_seed; 1164 const void *fdt = initial_boot_params; 1165 1166 node = fdt_path_offset(fdt, "/chosen"); 1167 if (node < 0) 1168 node = fdt_path_offset(fdt, "/chosen@0"); 1169 if (node < 0) 1170 return -ENOENT; 1171 1172 chosen_node_offset = node; 1173 1174 early_init_dt_check_for_initrd(node); 1175 early_init_dt_check_for_elfcorehdr(node); 1176 1177 /* Retrieve command line */ 1178 p = of_get_flat_dt_prop(node, "bootargs", &l); 1179 if (p != NULL && l > 0) 1180 strlcpy(cmdline, p, min(l, COMMAND_LINE_SIZE)); 1181 1182 /* 1183 * CONFIG_CMDLINE is meant to be a default in case nothing else 1184 * managed to set the command line, unless CONFIG_CMDLINE_FORCE 1185 * is set in which case we override whatever was found earlier. 1186 */ 1187 #ifdef CONFIG_CMDLINE 1188 #if defined(CONFIG_CMDLINE_EXTEND) 1189 strlcat(cmdline, " ", COMMAND_LINE_SIZE); 1190 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1191 #elif defined(CONFIG_CMDLINE_FORCE) 1192 strlcpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1193 #else 1194 /* No arguments from boot loader, use kernel's cmdl*/ 1195 if (!((char *)cmdline)[0]) 1196 strlcpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1197 #endif 1198 #endif /* CONFIG_CMDLINE */ 1199 1200 pr_debug("Command line is: %s\n", (char *)cmdline); 1201 1202 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l); 1203 if (rng_seed && l > 0) { 1204 add_bootloader_randomness(rng_seed, l); 1205 1206 /* try to clear seed so it won't be found. */ 1207 fdt_nop_property(initial_boot_params, node, "rng-seed"); 1208 1209 /* update CRC check value */ 1210 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1211 fdt_totalsize(initial_boot_params)); 1212 } 1213 1214 return 0; 1215 } 1216 1217 #ifndef MIN_MEMBLOCK_ADDR 1218 #define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET) 1219 #endif 1220 #ifndef MAX_MEMBLOCK_ADDR 1221 #define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0) 1222 #endif 1223 1224 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) 1225 { 1226 const u64 phys_offset = MIN_MEMBLOCK_ADDR; 1227 1228 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { 1229 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1230 base, base + size); 1231 return; 1232 } 1233 1234 if (!PAGE_ALIGNED(base)) { 1235 size -= PAGE_SIZE - (base & ~PAGE_MASK); 1236 base = PAGE_ALIGN(base); 1237 } 1238 size &= PAGE_MASK; 1239 1240 if (base > MAX_MEMBLOCK_ADDR) { 1241 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1242 base, base + size); 1243 return; 1244 } 1245 1246 if (base + size - 1 > MAX_MEMBLOCK_ADDR) { 1247 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", 1248 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size); 1249 size = MAX_MEMBLOCK_ADDR - base + 1; 1250 } 1251 1252 if (base + size < phys_offset) { 1253 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1254 base, base + size); 1255 return; 1256 } 1257 if (base < phys_offset) { 1258 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", 1259 base, phys_offset); 1260 size -= phys_offset - base; 1261 base = phys_offset; 1262 } 1263 memblock_add(base, size); 1264 } 1265 1266 static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align) 1267 { 1268 void *ptr = memblock_alloc(size, align); 1269 1270 if (!ptr) 1271 panic("%s: Failed to allocate %llu bytes align=0x%llx\n", 1272 __func__, size, align); 1273 1274 return ptr; 1275 } 1276 1277 bool __init early_init_dt_verify(void *params) 1278 { 1279 if (!params) 1280 return false; 1281 1282 /* check device tree validity */ 1283 if (fdt_check_header(params)) 1284 return false; 1285 1286 /* Setup flat device-tree pointer */ 1287 initial_boot_params = params; 1288 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1289 fdt_totalsize(initial_boot_params)); 1290 return true; 1291 } 1292 1293 1294 void __init early_init_dt_scan_nodes(void) 1295 { 1296 int rc; 1297 1298 /* Initialize {size,address}-cells info */ 1299 early_init_dt_scan_root(); 1300 1301 /* Retrieve various information from the /chosen node */ 1302 rc = early_init_dt_scan_chosen(boot_command_line); 1303 if (rc) 1304 pr_warn("No chosen node found, continuing without\n"); 1305 1306 /* Setup memory, calling early_init_dt_add_memory_arch */ 1307 early_init_dt_scan_memory(); 1308 1309 /* Handle linux,usable-memory-range property */ 1310 early_init_dt_check_for_usable_mem_range(); 1311 } 1312 1313 bool __init early_init_dt_scan(void *params) 1314 { 1315 bool status; 1316 1317 status = early_init_dt_verify(params); 1318 if (!status) 1319 return false; 1320 1321 early_init_dt_scan_nodes(); 1322 return true; 1323 } 1324 1325 /** 1326 * unflatten_device_tree - create tree of device_nodes from flat blob 1327 * 1328 * unflattens the device-tree passed by the firmware, creating the 1329 * tree of struct device_node. It also fills the "name" and "type" 1330 * pointers of the nodes so the normal device-tree walking functions 1331 * can be used. 1332 */ 1333 void __init unflatten_device_tree(void) 1334 { 1335 __unflatten_device_tree(initial_boot_params, NULL, &of_root, 1336 early_init_dt_alloc_memory_arch, false); 1337 1338 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ 1339 of_alias_scan(early_init_dt_alloc_memory_arch); 1340 1341 unittest_unflatten_overlay_base(); 1342 } 1343 1344 /** 1345 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob 1346 * 1347 * Copies and unflattens the device-tree passed by the firmware, creating the 1348 * tree of struct device_node. It also fills the "name" and "type" 1349 * pointers of the nodes so the normal device-tree walking functions 1350 * can be used. This should only be used when the FDT memory has not been 1351 * reserved such is the case when the FDT is built-in to the kernel init 1352 * section. If the FDT memory is reserved already then unflatten_device_tree 1353 * should be used instead. 1354 */ 1355 void __init unflatten_and_copy_device_tree(void) 1356 { 1357 int size; 1358 void *dt; 1359 1360 if (!initial_boot_params) { 1361 pr_warn("No valid device tree found, continuing without\n"); 1362 return; 1363 } 1364 1365 size = fdt_totalsize(initial_boot_params); 1366 dt = early_init_dt_alloc_memory_arch(size, 1367 roundup_pow_of_two(FDT_V17_SIZE)); 1368 1369 if (dt) { 1370 memcpy(dt, initial_boot_params, size); 1371 initial_boot_params = dt; 1372 } 1373 unflatten_device_tree(); 1374 } 1375 1376 #ifdef CONFIG_SYSFS 1377 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj, 1378 struct bin_attribute *bin_attr, 1379 char *buf, loff_t off, size_t count) 1380 { 1381 memcpy(buf, initial_boot_params + off, count); 1382 return count; 1383 } 1384 1385 static int __init of_fdt_raw_init(void) 1386 { 1387 static struct bin_attribute of_fdt_raw_attr = 1388 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0); 1389 1390 if (!initial_boot_params) 1391 return 0; 1392 1393 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params, 1394 fdt_totalsize(initial_boot_params))) { 1395 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n"); 1396 return 0; 1397 } 1398 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params); 1399 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr); 1400 } 1401 late_initcall(of_fdt_raw_init); 1402 #endif 1403 1404 #endif /* CONFIG_OF_EARLY_FLATTREE */ 1405