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