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. 487 */ 488 if (memblock_is_region_reserved(base, size)) 489 return -EBUSY; 490 491 return memblock_mark_nomap(base, size); 492 } 493 return memblock_reserve(base, size); 494 } 495 496 /* 497 * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property 498 */ 499 static int __init __reserved_mem_reserve_reg(unsigned long node, 500 const char *uname) 501 { 502 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32); 503 phys_addr_t base, size; 504 int len; 505 const __be32 *prop; 506 int first = 1; 507 bool nomap; 508 509 prop = of_get_flat_dt_prop(node, "reg", &len); 510 if (!prop) 511 return -ENOENT; 512 513 if (len && len % t_len != 0) { 514 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n", 515 uname); 516 return -EINVAL; 517 } 518 519 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL; 520 521 while (len >= t_len) { 522 base = dt_mem_next_cell(dt_root_addr_cells, &prop); 523 size = dt_mem_next_cell(dt_root_size_cells, &prop); 524 525 if (size && 526 early_init_dt_reserve_memory_arch(base, size, nomap) == 0) { 527 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n", 528 uname, &base, (unsigned long)(size / SZ_1M)); 529 if (!nomap) 530 kmemleak_alloc_phys(base, size, 0, 0); 531 } 532 else 533 pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n", 534 uname, &base, (unsigned long)(size / SZ_1M)); 535 536 len -= t_len; 537 if (first) { 538 fdt_reserved_mem_save_node(node, uname, base, size); 539 first = 0; 540 } 541 } 542 return 0; 543 } 544 545 /* 546 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided 547 * in /reserved-memory matches the values supported by the current implementation, 548 * also check if ranges property has been provided 549 */ 550 static int __init __reserved_mem_check_root(unsigned long node) 551 { 552 const __be32 *prop; 553 554 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 555 if (!prop || be32_to_cpup(prop) != dt_root_size_cells) 556 return -EINVAL; 557 558 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 559 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells) 560 return -EINVAL; 561 562 prop = of_get_flat_dt_prop(node, "ranges", NULL); 563 if (!prop) 564 return -EINVAL; 565 return 0; 566 } 567 568 /* 569 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory 570 */ 571 static int __init fdt_scan_reserved_mem(void) 572 { 573 int node, child; 574 const void *fdt = initial_boot_params; 575 576 node = fdt_path_offset(fdt, "/reserved-memory"); 577 if (node < 0) 578 return -ENODEV; 579 580 if (__reserved_mem_check_root(node) != 0) { 581 pr_err("Reserved memory: unsupported node format, ignoring\n"); 582 return -EINVAL; 583 } 584 585 fdt_for_each_subnode(child, fdt, node) { 586 const char *uname; 587 int err; 588 589 if (!of_fdt_device_is_available(fdt, child)) 590 continue; 591 592 uname = fdt_get_name(fdt, child, NULL); 593 594 err = __reserved_mem_reserve_reg(child, uname); 595 if (err == -ENOENT && of_get_flat_dt_prop(child, "size", NULL)) 596 fdt_reserved_mem_save_node(child, uname, 0, 0); 597 } 598 return 0; 599 } 600 601 /* 602 * fdt_reserve_elfcorehdr() - reserves memory for elf core header 603 * 604 * This function reserves the memory occupied by an elf core header 605 * described in the device tree. This region contains all the 606 * information about primary kernel's core image and is used by a dump 607 * capture kernel to access the system memory on primary kernel. 608 */ 609 static void __init fdt_reserve_elfcorehdr(void) 610 { 611 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size) 612 return; 613 614 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) { 615 pr_warn("elfcorehdr is overlapped\n"); 616 return; 617 } 618 619 memblock_reserve(elfcorehdr_addr, elfcorehdr_size); 620 621 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n", 622 elfcorehdr_size >> 10, elfcorehdr_addr); 623 } 624 625 /** 626 * early_init_fdt_scan_reserved_mem() - create reserved memory regions 627 * 628 * This function grabs memory from early allocator for device exclusive use 629 * defined in device tree structures. It should be called by arch specific code 630 * once the early allocator (i.e. memblock) has been fully activated. 631 */ 632 void __init early_init_fdt_scan_reserved_mem(void) 633 { 634 int n; 635 u64 base, size; 636 637 if (!initial_boot_params) 638 return; 639 640 /* Process header /memreserve/ fields */ 641 for (n = 0; ; n++) { 642 fdt_get_mem_rsv(initial_boot_params, n, &base, &size); 643 if (!size) 644 break; 645 early_init_dt_reserve_memory_arch(base, size, false); 646 } 647 648 fdt_scan_reserved_mem(); 649 fdt_init_reserved_mem(); 650 fdt_reserve_elfcorehdr(); 651 } 652 653 /** 654 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob 655 */ 656 void __init early_init_fdt_reserve_self(void) 657 { 658 if (!initial_boot_params) 659 return; 660 661 /* Reserve the dtb region */ 662 early_init_dt_reserve_memory_arch(__pa(initial_boot_params), 663 fdt_totalsize(initial_boot_params), 664 false); 665 } 666 667 /** 668 * of_scan_flat_dt - scan flattened tree blob and call callback on each. 669 * @it: callback function 670 * @data: context data pointer 671 * 672 * This function is used to scan the flattened device-tree, it is 673 * used to extract the memory information at boot before we can 674 * unflatten the tree 675 */ 676 int __init of_scan_flat_dt(int (*it)(unsigned long node, 677 const char *uname, int depth, 678 void *data), 679 void *data) 680 { 681 const void *blob = initial_boot_params; 682 const char *pathp; 683 int offset, rc = 0, depth = -1; 684 685 if (!blob) 686 return 0; 687 688 for (offset = fdt_next_node(blob, -1, &depth); 689 offset >= 0 && depth >= 0 && !rc; 690 offset = fdt_next_node(blob, offset, &depth)) { 691 692 pathp = fdt_get_name(blob, offset, NULL); 693 rc = it(offset, pathp, depth, data); 694 } 695 return rc; 696 } 697 698 /** 699 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each. 700 * @parent: parent node 701 * @it: callback function 702 * @data: context data pointer 703 * 704 * This function is used to scan sub-nodes of a node. 705 */ 706 int __init of_scan_flat_dt_subnodes(unsigned long parent, 707 int (*it)(unsigned long node, 708 const char *uname, 709 void *data), 710 void *data) 711 { 712 const void *blob = initial_boot_params; 713 int node; 714 715 fdt_for_each_subnode(node, blob, parent) { 716 const char *pathp; 717 int rc; 718 719 pathp = fdt_get_name(blob, node, NULL); 720 rc = it(node, pathp, data); 721 if (rc) 722 return rc; 723 } 724 return 0; 725 } 726 727 /** 728 * of_get_flat_dt_subnode_by_name - get the subnode by given name 729 * 730 * @node: the parent node 731 * @uname: the name of subnode 732 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none 733 */ 734 735 int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) 736 { 737 return fdt_subnode_offset(initial_boot_params, node, uname); 738 } 739 740 /* 741 * of_get_flat_dt_root - find the root node in the flat blob 742 */ 743 unsigned long __init of_get_flat_dt_root(void) 744 { 745 return 0; 746 } 747 748 /* 749 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr 750 * 751 * This function can be used within scan_flattened_dt callback to get 752 * access to properties 753 */ 754 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name, 755 int *size) 756 { 757 return fdt_getprop(initial_boot_params, node, name, size); 758 } 759 760 /** 761 * of_fdt_is_compatible - Return true if given node from the given blob has 762 * compat in its compatible list 763 * @blob: A device tree blob 764 * @node: node to test 765 * @compat: compatible string to compare with compatible list. 766 * 767 * Return: a non-zero value on match with smaller values returned for more 768 * specific compatible values. 769 */ 770 static int of_fdt_is_compatible(const void *blob, 771 unsigned long node, const char *compat) 772 { 773 const char *cp; 774 int cplen; 775 unsigned long l, score = 0; 776 777 cp = fdt_getprop(blob, node, "compatible", &cplen); 778 if (cp == NULL) 779 return 0; 780 while (cplen > 0) { 781 score++; 782 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) 783 return score; 784 l = strlen(cp) + 1; 785 cp += l; 786 cplen -= l; 787 } 788 789 return 0; 790 } 791 792 /** 793 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list 794 * @node: node to test 795 * @compat: compatible string to compare with compatible list. 796 */ 797 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat) 798 { 799 return of_fdt_is_compatible(initial_boot_params, node, compat); 800 } 801 802 /* 803 * of_flat_dt_match - Return true if node matches a list of compatible values 804 */ 805 static int __init of_flat_dt_match(unsigned long node, const char *const *compat) 806 { 807 unsigned int tmp, score = 0; 808 809 if (!compat) 810 return 0; 811 812 while (*compat) { 813 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat); 814 if (tmp && (score == 0 || (tmp < score))) 815 score = tmp; 816 compat++; 817 } 818 819 return score; 820 } 821 822 /* 823 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle 824 */ 825 uint32_t __init of_get_flat_dt_phandle(unsigned long node) 826 { 827 return fdt_get_phandle(initial_boot_params, node); 828 } 829 830 struct fdt_scan_status { 831 const char *name; 832 int namelen; 833 int depth; 834 int found; 835 int (*iterator)(unsigned long node, const char *uname, int depth, void *data); 836 void *data; 837 }; 838 839 const char * __init of_flat_dt_get_machine_name(void) 840 { 841 const char *name; 842 unsigned long dt_root = of_get_flat_dt_root(); 843 844 name = of_get_flat_dt_prop(dt_root, "model", NULL); 845 if (!name) 846 name = of_get_flat_dt_prop(dt_root, "compatible", NULL); 847 return name; 848 } 849 850 /** 851 * of_flat_dt_match_machine - Iterate match tables to find matching machine. 852 * 853 * @default_match: A machine specific ptr to return in case of no match. 854 * @get_next_compat: callback function to return next compatible match table. 855 * 856 * Iterate through machine match tables to find the best match for the machine 857 * compatible string in the FDT. 858 */ 859 const void * __init of_flat_dt_match_machine(const void *default_match, 860 const void * (*get_next_compat)(const char * const**)) 861 { 862 const void *data = NULL; 863 const void *best_data = default_match; 864 const char *const *compat; 865 unsigned long dt_root; 866 unsigned int best_score = ~1, score = 0; 867 868 dt_root = of_get_flat_dt_root(); 869 while ((data = get_next_compat(&compat))) { 870 score = of_flat_dt_match(dt_root, compat); 871 if (score > 0 && score < best_score) { 872 best_data = data; 873 best_score = score; 874 } 875 } 876 if (!best_data) { 877 const char *prop; 878 int size; 879 880 pr_err("\n unrecognized device tree list:\n[ "); 881 882 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 883 if (prop) { 884 while (size > 0) { 885 printk("'%s' ", prop); 886 size -= strlen(prop) + 1; 887 prop += strlen(prop) + 1; 888 } 889 } 890 printk("]\n\n"); 891 return NULL; 892 } 893 894 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name()); 895 896 return best_data; 897 } 898 899 static void __early_init_dt_declare_initrd(unsigned long start, 900 unsigned long end) 901 { 902 /* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is 903 * enabled since __va() is called too early. ARM64 does make use 904 * of phys_initrd_start/phys_initrd_size so we can skip this 905 * conversion. 906 */ 907 if (!IS_ENABLED(CONFIG_ARM64)) { 908 initrd_start = (unsigned long)__va(start); 909 initrd_end = (unsigned long)__va(end); 910 initrd_below_start_ok = 1; 911 } 912 } 913 914 /** 915 * early_init_dt_check_for_initrd - Decode initrd location from flat tree 916 * @node: reference to node containing initrd location ('chosen') 917 */ 918 static void __init early_init_dt_check_for_initrd(unsigned long node) 919 { 920 u64 start, end; 921 int len; 922 const __be32 *prop; 923 924 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD)) 925 return; 926 927 pr_debug("Looking for initrd properties... "); 928 929 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len); 930 if (!prop) 931 return; 932 start = of_read_number(prop, len/4); 933 934 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len); 935 if (!prop) 936 return; 937 end = of_read_number(prop, len/4); 938 939 __early_init_dt_declare_initrd(start, end); 940 phys_initrd_start = start; 941 phys_initrd_size = end - start; 942 943 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end); 944 } 945 946 /** 947 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat 948 * tree 949 * @node: reference to node containing elfcorehdr location ('chosen') 950 */ 951 static void __init early_init_dt_check_for_elfcorehdr(unsigned long node) 952 { 953 const __be32 *prop; 954 int len; 955 956 if (!IS_ENABLED(CONFIG_CRASH_DUMP)) 957 return; 958 959 pr_debug("Looking for elfcorehdr property... "); 960 961 prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len); 962 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells))) 963 return; 964 965 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); 966 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop); 967 968 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n", 969 elfcorehdr_addr, elfcorehdr_size); 970 } 971 972 static phys_addr_t cap_mem_addr; 973 static phys_addr_t cap_mem_size; 974 975 /** 976 * early_init_dt_check_for_usable_mem_range - Decode usable memory range 977 * location from flat tree 978 * @node: reference to node containing usable memory range location ('chosen') 979 */ 980 static void __init early_init_dt_check_for_usable_mem_range(unsigned long node) 981 { 982 const __be32 *prop; 983 int len; 984 985 pr_debug("Looking for usable-memory-range property... "); 986 987 prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); 988 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells))) 989 return; 990 991 cap_mem_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); 992 cap_mem_size = dt_mem_next_cell(dt_root_size_cells, &prop); 993 994 pr_debug("cap_mem_start=%pa cap_mem_size=%pa\n", &cap_mem_addr, 995 &cap_mem_size); 996 } 997 998 #ifdef CONFIG_SERIAL_EARLYCON 999 1000 int __init early_init_dt_scan_chosen_stdout(void) 1001 { 1002 int offset; 1003 const char *p, *q, *options = NULL; 1004 int l; 1005 const struct earlycon_id *match; 1006 const void *fdt = initial_boot_params; 1007 1008 offset = fdt_path_offset(fdt, "/chosen"); 1009 if (offset < 0) 1010 offset = fdt_path_offset(fdt, "/chosen@0"); 1011 if (offset < 0) 1012 return -ENOENT; 1013 1014 p = fdt_getprop(fdt, offset, "stdout-path", &l); 1015 if (!p) 1016 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l); 1017 if (!p || !l) 1018 return -ENOENT; 1019 1020 q = strchrnul(p, ':'); 1021 if (*q != '\0') 1022 options = q + 1; 1023 l = q - p; 1024 1025 /* Get the node specified by stdout-path */ 1026 offset = fdt_path_offset_namelen(fdt, p, l); 1027 if (offset < 0) { 1028 pr_warn("earlycon: stdout-path %.*s not found\n", l, p); 1029 return 0; 1030 } 1031 1032 for (match = __earlycon_table; match < __earlycon_table_end; match++) { 1033 if (!match->compatible[0]) 1034 continue; 1035 1036 if (fdt_node_check_compatible(fdt, offset, match->compatible)) 1037 continue; 1038 1039 if (of_setup_earlycon(match, offset, options) == 0) 1040 return 0; 1041 } 1042 return -ENODEV; 1043 } 1044 #endif 1045 1046 /* 1047 * early_init_dt_scan_root - fetch the top level address and size cells 1048 */ 1049 int __init early_init_dt_scan_root(unsigned long node, const char *uname, 1050 int depth, void *data) 1051 { 1052 const __be32 *prop; 1053 1054 if (depth != 0) 1055 return 0; 1056 1057 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 1058 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 1059 1060 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 1061 if (prop) 1062 dt_root_size_cells = be32_to_cpup(prop); 1063 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells); 1064 1065 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 1066 if (prop) 1067 dt_root_addr_cells = be32_to_cpup(prop); 1068 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells); 1069 1070 /* break now */ 1071 return 1; 1072 } 1073 1074 u64 __init dt_mem_next_cell(int s, const __be32 **cellp) 1075 { 1076 const __be32 *p = *cellp; 1077 1078 *cellp = p + s; 1079 return of_read_number(p, s); 1080 } 1081 1082 /* 1083 * early_init_dt_scan_memory - Look for and parse memory nodes 1084 */ 1085 int __init early_init_dt_scan_memory(unsigned long node, const char *uname, 1086 int depth, void *data) 1087 { 1088 const char *type = of_get_flat_dt_prop(node, "device_type", NULL); 1089 const __be32 *reg, *endp; 1090 int l; 1091 bool hotpluggable; 1092 1093 /* We are scanning "memory" nodes only */ 1094 if (type == NULL || strcmp(type, "memory") != 0) 1095 return 0; 1096 1097 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l); 1098 if (reg == NULL) 1099 reg = of_get_flat_dt_prop(node, "reg", &l); 1100 if (reg == NULL) 1101 return 0; 1102 1103 endp = reg + (l / sizeof(__be32)); 1104 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL); 1105 1106 pr_debug("memory scan node %s, reg size %d,\n", uname, l); 1107 1108 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) { 1109 u64 base, size; 1110 1111 base = dt_mem_next_cell(dt_root_addr_cells, ®); 1112 size = dt_mem_next_cell(dt_root_size_cells, ®); 1113 1114 if (size == 0) 1115 continue; 1116 pr_debug(" - %llx, %llx\n", base, size); 1117 1118 early_init_dt_add_memory_arch(base, size); 1119 1120 if (!hotpluggable) 1121 continue; 1122 1123 if (memblock_mark_hotplug(base, size)) 1124 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n", 1125 base, base + size); 1126 } 1127 1128 return 0; 1129 } 1130 1131 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, 1132 int depth, void *data) 1133 { 1134 int l; 1135 const char *p; 1136 const void *rng_seed; 1137 1138 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); 1139 1140 if (depth != 1 || !data || 1141 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0)) 1142 return 0; 1143 1144 early_init_dt_check_for_initrd(node); 1145 early_init_dt_check_for_elfcorehdr(node); 1146 early_init_dt_check_for_usable_mem_range(node); 1147 1148 /* Retrieve command line */ 1149 p = of_get_flat_dt_prop(node, "bootargs", &l); 1150 if (p != NULL && l > 0) 1151 strlcpy(data, p, min(l, COMMAND_LINE_SIZE)); 1152 1153 /* 1154 * CONFIG_CMDLINE is meant to be a default in case nothing else 1155 * managed to set the command line, unless CONFIG_CMDLINE_FORCE 1156 * is set in which case we override whatever was found earlier. 1157 */ 1158 #ifdef CONFIG_CMDLINE 1159 #if defined(CONFIG_CMDLINE_EXTEND) 1160 strlcat(data, " ", COMMAND_LINE_SIZE); 1161 strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1162 #elif defined(CONFIG_CMDLINE_FORCE) 1163 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1164 #else 1165 /* No arguments from boot loader, use kernel's cmdl*/ 1166 if (!((char *)data)[0]) 1167 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1168 #endif 1169 #endif /* CONFIG_CMDLINE */ 1170 1171 pr_debug("Command line is: %s\n", (char *)data); 1172 1173 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l); 1174 if (rng_seed && l > 0) { 1175 add_bootloader_randomness(rng_seed, l); 1176 1177 /* try to clear seed so it won't be found. */ 1178 fdt_nop_property(initial_boot_params, node, "rng-seed"); 1179 1180 /* update CRC check value */ 1181 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1182 fdt_totalsize(initial_boot_params)); 1183 } 1184 1185 /* break now */ 1186 return 1; 1187 } 1188 1189 #ifndef MIN_MEMBLOCK_ADDR 1190 #define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET) 1191 #endif 1192 #ifndef MAX_MEMBLOCK_ADDR 1193 #define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0) 1194 #endif 1195 1196 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) 1197 { 1198 const u64 phys_offset = MIN_MEMBLOCK_ADDR; 1199 1200 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { 1201 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1202 base, base + size); 1203 return; 1204 } 1205 1206 if (!PAGE_ALIGNED(base)) { 1207 size -= PAGE_SIZE - (base & ~PAGE_MASK); 1208 base = PAGE_ALIGN(base); 1209 } 1210 size &= PAGE_MASK; 1211 1212 if (base > MAX_MEMBLOCK_ADDR) { 1213 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1214 base, base + size); 1215 return; 1216 } 1217 1218 if (base + size - 1 > MAX_MEMBLOCK_ADDR) { 1219 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", 1220 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size); 1221 size = MAX_MEMBLOCK_ADDR - base + 1; 1222 } 1223 1224 if (base + size < phys_offset) { 1225 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1226 base, base + size); 1227 return; 1228 } 1229 if (base < phys_offset) { 1230 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", 1231 base, phys_offset); 1232 size -= phys_offset - base; 1233 base = phys_offset; 1234 } 1235 memblock_add(base, size); 1236 } 1237 1238 static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align) 1239 { 1240 void *ptr = memblock_alloc(size, align); 1241 1242 if (!ptr) 1243 panic("%s: Failed to allocate %llu bytes align=0x%llx\n", 1244 __func__, size, align); 1245 1246 return ptr; 1247 } 1248 1249 bool __init early_init_dt_verify(void *params) 1250 { 1251 if (!params) 1252 return false; 1253 1254 /* check device tree validity */ 1255 if (fdt_check_header(params)) 1256 return false; 1257 1258 /* Setup flat device-tree pointer */ 1259 initial_boot_params = params; 1260 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1261 fdt_totalsize(initial_boot_params)); 1262 return true; 1263 } 1264 1265 1266 void __init early_init_dt_scan_nodes(void) 1267 { 1268 int rc = 0; 1269 1270 /* Initialize {size,address}-cells info */ 1271 of_scan_flat_dt(early_init_dt_scan_root, NULL); 1272 1273 /* Retrieve various information from the /chosen node */ 1274 rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); 1275 if (!rc) 1276 pr_warn("No chosen node found, continuing without\n"); 1277 1278 /* Setup memory, calling early_init_dt_add_memory_arch */ 1279 of_scan_flat_dt(early_init_dt_scan_memory, NULL); 1280 1281 /* Handle linux,usable-memory-range property */ 1282 memblock_cap_memory_range(cap_mem_addr, cap_mem_size); 1283 } 1284 1285 bool __init early_init_dt_scan(void *params) 1286 { 1287 bool status; 1288 1289 status = early_init_dt_verify(params); 1290 if (!status) 1291 return false; 1292 1293 early_init_dt_scan_nodes(); 1294 return true; 1295 } 1296 1297 /** 1298 * unflatten_device_tree - create tree of device_nodes from flat blob 1299 * 1300 * unflattens the device-tree passed by the firmware, creating the 1301 * tree of struct device_node. It also fills the "name" and "type" 1302 * pointers of the nodes so the normal device-tree walking functions 1303 * can be used. 1304 */ 1305 void __init unflatten_device_tree(void) 1306 { 1307 __unflatten_device_tree(initial_boot_params, NULL, &of_root, 1308 early_init_dt_alloc_memory_arch, false); 1309 1310 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ 1311 of_alias_scan(early_init_dt_alloc_memory_arch); 1312 1313 unittest_unflatten_overlay_base(); 1314 } 1315 1316 /** 1317 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob 1318 * 1319 * Copies and unflattens the device-tree passed by the firmware, creating the 1320 * tree of struct device_node. It also fills the "name" and "type" 1321 * pointers of the nodes so the normal device-tree walking functions 1322 * can be used. This should only be used when the FDT memory has not been 1323 * reserved such is the case when the FDT is built-in to the kernel init 1324 * section. If the FDT memory is reserved already then unflatten_device_tree 1325 * should be used instead. 1326 */ 1327 void __init unflatten_and_copy_device_tree(void) 1328 { 1329 int size; 1330 void *dt; 1331 1332 if (!initial_boot_params) { 1333 pr_warn("No valid device tree found, continuing without\n"); 1334 return; 1335 } 1336 1337 size = fdt_totalsize(initial_boot_params); 1338 dt = early_init_dt_alloc_memory_arch(size, 1339 roundup_pow_of_two(FDT_V17_SIZE)); 1340 1341 if (dt) { 1342 memcpy(dt, initial_boot_params, size); 1343 initial_boot_params = dt; 1344 } 1345 unflatten_device_tree(); 1346 } 1347 1348 #ifdef CONFIG_SYSFS 1349 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj, 1350 struct bin_attribute *bin_attr, 1351 char *buf, loff_t off, size_t count) 1352 { 1353 memcpy(buf, initial_boot_params + off, count); 1354 return count; 1355 } 1356 1357 static int __init of_fdt_raw_init(void) 1358 { 1359 static struct bin_attribute of_fdt_raw_attr = 1360 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0); 1361 1362 if (!initial_boot_params) 1363 return 0; 1364 1365 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params, 1366 fdt_totalsize(initial_boot_params))) { 1367 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n"); 1368 return 0; 1369 } 1370 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params); 1371 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr); 1372 } 1373 late_initcall(of_fdt_raw_init); 1374 #endif 1375 1376 #endif /* CONFIG_OF_EARLY_FLATTREE */ 1377