1 /* 2 * Functions for working with the Flattened Device Tree data format 3 * 4 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp 5 * benh@kernel.crashing.org 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * version 2 as published by the Free Software Foundation. 10 */ 11 12 #define pr_fmt(fmt) "OF: fdt: " fmt 13 14 #include <linux/crc32.h> 15 #include <linux/kernel.h> 16 #include <linux/initrd.h> 17 #include <linux/memblock.h> 18 #include <linux/mutex.h> 19 #include <linux/of.h> 20 #include <linux/of_fdt.h> 21 #include <linux/of_reserved_mem.h> 22 #include <linux/sizes.h> 23 #include <linux/string.h> 24 #include <linux/errno.h> 25 #include <linux/slab.h> 26 #include <linux/libfdt.h> 27 #include <linux/debugfs.h> 28 #include <linux/serial_core.h> 29 #include <linux/sysfs.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 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 /** 85 * of_fdt_is_compatible - Return true if given node from the given blob has 86 * compat in its compatible list 87 * @blob: A device tree blob 88 * @node: node to test 89 * @compat: compatible string to compare with compatible list. 90 * 91 * On match, returns a non-zero value with smaller values returned for more 92 * specific compatible values. 93 */ 94 static int of_fdt_is_compatible(const void *blob, 95 unsigned long node, const char *compat) 96 { 97 const char *cp; 98 int cplen; 99 unsigned long l, score = 0; 100 101 cp = fdt_getprop(blob, node, "compatible", &cplen); 102 if (cp == NULL) 103 return 0; 104 while (cplen > 0) { 105 score++; 106 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) 107 return score; 108 l = strlen(cp) + 1; 109 cp += l; 110 cplen -= l; 111 } 112 113 return 0; 114 } 115 116 /** 117 * of_fdt_is_big_endian - Return true if given node needs BE MMIO accesses 118 * @blob: A device tree blob 119 * @node: node to test 120 * 121 * Returns true if the node has a "big-endian" property, or if the kernel 122 * was compiled for BE *and* the node has a "native-endian" property. 123 * Returns false otherwise. 124 */ 125 bool of_fdt_is_big_endian(const void *blob, unsigned long node) 126 { 127 if (fdt_getprop(blob, node, "big-endian", NULL)) 128 return true; 129 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) && 130 fdt_getprop(blob, node, "native-endian", NULL)) 131 return true; 132 return false; 133 } 134 135 /** 136 * of_fdt_match - Return true if node matches a list of compatible values 137 */ 138 int of_fdt_match(const void *blob, unsigned long node, 139 const char *const *compat) 140 { 141 unsigned int tmp, score = 0; 142 143 if (!compat) 144 return 0; 145 146 while (*compat) { 147 tmp = of_fdt_is_compatible(blob, node, *compat); 148 if (tmp && (score == 0 || (tmp < score))) 149 score = tmp; 150 compat++; 151 } 152 153 return score; 154 } 155 156 static void *unflatten_dt_alloc(void **mem, unsigned long size, 157 unsigned long align) 158 { 159 void *res; 160 161 *mem = PTR_ALIGN(*mem, align); 162 res = *mem; 163 *mem += size; 164 165 return res; 166 } 167 168 static void populate_properties(const void *blob, 169 int offset, 170 void **mem, 171 struct device_node *np, 172 const char *nodename, 173 bool dryrun) 174 { 175 struct property *pp, **pprev = NULL; 176 int cur; 177 bool has_name = false; 178 179 pprev = &np->properties; 180 for (cur = fdt_first_property_offset(blob, offset); 181 cur >= 0; 182 cur = fdt_next_property_offset(blob, cur)) { 183 const __be32 *val; 184 const char *pname; 185 u32 sz; 186 187 val = fdt_getprop_by_offset(blob, cur, &pname, &sz); 188 if (!val) { 189 pr_warn("Cannot locate property at 0x%x\n", cur); 190 continue; 191 } 192 193 if (!pname) { 194 pr_warn("Cannot find property name at 0x%x\n", cur); 195 continue; 196 } 197 198 if (!strcmp(pname, "name")) 199 has_name = true; 200 201 pp = unflatten_dt_alloc(mem, sizeof(struct property), 202 __alignof__(struct property)); 203 if (dryrun) 204 continue; 205 206 /* We accept flattened tree phandles either in 207 * ePAPR-style "phandle" properties, or the 208 * legacy "linux,phandle" properties. If both 209 * appear and have different values, things 210 * will get weird. Don't do that. 211 */ 212 if (!strcmp(pname, "phandle") || 213 !strcmp(pname, "linux,phandle")) { 214 if (!np->phandle) 215 np->phandle = be32_to_cpup(val); 216 } 217 218 /* And we process the "ibm,phandle" property 219 * used in pSeries dynamic device tree 220 * stuff 221 */ 222 if (!strcmp(pname, "ibm,phandle")) 223 np->phandle = be32_to_cpup(val); 224 225 pp->name = (char *)pname; 226 pp->length = sz; 227 pp->value = (__be32 *)val; 228 *pprev = pp; 229 pprev = &pp->next; 230 } 231 232 /* With version 0x10 we may not have the name property, 233 * recreate it here from the unit name if absent 234 */ 235 if (!has_name) { 236 const char *p = nodename, *ps = p, *pa = NULL; 237 int len; 238 239 while (*p) { 240 if ((*p) == '@') 241 pa = p; 242 else if ((*p) == '/') 243 ps = p + 1; 244 p++; 245 } 246 247 if (pa < ps) 248 pa = p; 249 len = (pa - ps) + 1; 250 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len, 251 __alignof__(struct property)); 252 if (!dryrun) { 253 pp->name = "name"; 254 pp->length = len; 255 pp->value = pp + 1; 256 *pprev = pp; 257 pprev = &pp->next; 258 memcpy(pp->value, ps, len - 1); 259 ((char *)pp->value)[len - 1] = 0; 260 pr_debug("fixed up name for %s -> %s\n", 261 nodename, (char *)pp->value); 262 } 263 } 264 265 if (!dryrun) 266 *pprev = NULL; 267 } 268 269 static unsigned int populate_node(const void *blob, 270 int offset, 271 void **mem, 272 struct device_node *dad, 273 unsigned int fpsize, 274 struct device_node **pnp, 275 bool dryrun) 276 { 277 struct device_node *np; 278 const char *pathp; 279 unsigned int l, allocl; 280 int new_format = 0; 281 282 pathp = fdt_get_name(blob, offset, &l); 283 if (!pathp) { 284 *pnp = NULL; 285 return 0; 286 } 287 288 allocl = ++l; 289 290 /* version 0x10 has a more compact unit name here instead of the full 291 * path. we accumulate the full path size using "fpsize", we'll rebuild 292 * it later. We detect this because the first character of the name is 293 * not '/'. 294 */ 295 if ((*pathp) != '/') { 296 new_format = 1; 297 if (fpsize == 0) { 298 /* root node: special case. fpsize accounts for path 299 * plus terminating zero. root node only has '/', so 300 * fpsize should be 2, but we want to avoid the first 301 * level nodes to have two '/' so we use fpsize 1 here 302 */ 303 fpsize = 1; 304 allocl = 2; 305 l = 1; 306 pathp = ""; 307 } else { 308 /* account for '/' and path size minus terminal 0 309 * already in 'l' 310 */ 311 fpsize += l; 312 allocl = fpsize; 313 } 314 } 315 316 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl, 317 __alignof__(struct device_node)); 318 if (!dryrun) { 319 char *fn; 320 of_node_init(np); 321 np->full_name = fn = ((char *)np) + sizeof(*np); 322 if (new_format) { 323 /* rebuild full path for new format */ 324 if (dad && dad->parent) { 325 strcpy(fn, dad->full_name); 326 #ifdef DEBUG 327 if ((strlen(fn) + l + 1) != allocl) { 328 pr_debug("%s: p: %d, l: %d, a: %d\n", 329 pathp, (int)strlen(fn), 330 l, allocl); 331 } 332 #endif 333 fn += strlen(fn); 334 } 335 *(fn++) = '/'; 336 } 337 memcpy(fn, pathp, l); 338 339 if (dad != NULL) { 340 np->parent = dad; 341 np->sibling = dad->child; 342 dad->child = np; 343 } 344 } 345 346 populate_properties(blob, offset, mem, np, pathp, dryrun); 347 if (!dryrun) { 348 np->name = of_get_property(np, "name", NULL); 349 np->type = of_get_property(np, "device_type", NULL); 350 351 if (!np->name) 352 np->name = "<NULL>"; 353 if (!np->type) 354 np->type = "<NULL>"; 355 } 356 357 *pnp = np; 358 return fpsize; 359 } 360 361 static void reverse_nodes(struct device_node *parent) 362 { 363 struct device_node *child, *next; 364 365 /* In-depth first */ 366 child = parent->child; 367 while (child) { 368 reverse_nodes(child); 369 370 child = child->sibling; 371 } 372 373 /* Reverse the nodes in the child list */ 374 child = parent->child; 375 parent->child = NULL; 376 while (child) { 377 next = child->sibling; 378 379 child->sibling = parent->child; 380 parent->child = child; 381 child = next; 382 } 383 } 384 385 /** 386 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree 387 * @blob: The parent device tree blob 388 * @mem: Memory chunk to use for allocating device nodes and properties 389 * @dad: Parent struct device_node 390 * @nodepp: The device_node tree created by the call 391 * 392 * It returns the size of unflattened device tree or error code 393 */ 394 static int unflatten_dt_nodes(const void *blob, 395 void *mem, 396 struct device_node *dad, 397 struct device_node **nodepp) 398 { 399 struct device_node *root; 400 int offset = 0, depth = 0, initial_depth = 0; 401 #define FDT_MAX_DEPTH 64 402 unsigned int fpsizes[FDT_MAX_DEPTH]; 403 struct device_node *nps[FDT_MAX_DEPTH]; 404 void *base = mem; 405 bool dryrun = !base; 406 407 if (nodepp) 408 *nodepp = NULL; 409 410 /* 411 * We're unflattening device sub-tree if @dad is valid. There are 412 * possibly multiple nodes in the first level of depth. We need 413 * set @depth to 1 to make fdt_next_node() happy as it bails 414 * immediately when negative @depth is found. Otherwise, the device 415 * nodes except the first one won't be unflattened successfully. 416 */ 417 if (dad) 418 depth = initial_depth = 1; 419 420 root = dad; 421 fpsizes[depth] = dad ? strlen(of_node_full_name(dad)) : 0; 422 nps[depth] = dad; 423 424 for (offset = 0; 425 offset >= 0 && depth >= initial_depth; 426 offset = fdt_next_node(blob, offset, &depth)) { 427 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH)) 428 continue; 429 430 fpsizes[depth+1] = populate_node(blob, offset, &mem, 431 nps[depth], 432 fpsizes[depth], 433 &nps[depth+1], dryrun); 434 if (!fpsizes[depth+1]) 435 return mem - base; 436 437 if (!dryrun && nodepp && !*nodepp) 438 *nodepp = nps[depth+1]; 439 if (!dryrun && !root) 440 root = nps[depth+1]; 441 } 442 443 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) { 444 pr_err("Error %d processing FDT\n", offset); 445 return -EINVAL; 446 } 447 448 /* 449 * Reverse the child list. Some drivers assumes node order matches .dts 450 * node order 451 */ 452 if (!dryrun) 453 reverse_nodes(root); 454 455 return mem - base; 456 } 457 458 /** 459 * __unflatten_device_tree - create tree of device_nodes from flat blob 460 * 461 * unflattens a device-tree, creating the 462 * tree of struct device_node. It also fills the "name" and "type" 463 * pointers of the nodes so the normal device-tree walking functions 464 * can be used. 465 * @blob: The blob to expand 466 * @dad: Parent device node 467 * @mynodes: The device_node tree created by the call 468 * @dt_alloc: An allocator that provides a virtual address to memory 469 * for the resulting tree 470 * 471 * Returns NULL on failure or the memory chunk containing the unflattened 472 * device tree on success. 473 */ 474 void *__unflatten_device_tree(const void *blob, 475 struct device_node *dad, 476 struct device_node **mynodes, 477 void *(*dt_alloc)(u64 size, u64 align), 478 bool detached) 479 { 480 int size; 481 void *mem; 482 483 pr_debug(" -> unflatten_device_tree()\n"); 484 485 if (!blob) { 486 pr_debug("No device tree pointer\n"); 487 return NULL; 488 } 489 490 pr_debug("Unflattening device tree:\n"); 491 pr_debug("magic: %08x\n", fdt_magic(blob)); 492 pr_debug("size: %08x\n", fdt_totalsize(blob)); 493 pr_debug("version: %08x\n", fdt_version(blob)); 494 495 if (fdt_check_header(blob)) { 496 pr_err("Invalid device tree blob header\n"); 497 return NULL; 498 } 499 500 /* First pass, scan for size */ 501 size = unflatten_dt_nodes(blob, NULL, dad, NULL); 502 if (size < 0) 503 return NULL; 504 505 size = ALIGN(size, 4); 506 pr_debug(" size is %d, allocating...\n", size); 507 508 /* Allocate memory for the expanded device tree */ 509 mem = dt_alloc(size + 4, __alignof__(struct device_node)); 510 if (!mem) 511 return NULL; 512 513 memset(mem, 0, size); 514 515 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef); 516 517 pr_debug(" unflattening %p...\n", mem); 518 519 /* Second pass, do actual unflattening */ 520 unflatten_dt_nodes(blob, mem, dad, mynodes); 521 if (be32_to_cpup(mem + size) != 0xdeadbeef) 522 pr_warning("End of tree marker overwritten: %08x\n", 523 be32_to_cpup(mem + size)); 524 525 if (detached && mynodes) { 526 of_node_set_flag(*mynodes, OF_DETACHED); 527 pr_debug("unflattened tree is detached\n"); 528 } 529 530 pr_debug(" <- unflatten_device_tree()\n"); 531 return mem; 532 } 533 534 static void *kernel_tree_alloc(u64 size, u64 align) 535 { 536 return kzalloc(size, GFP_KERNEL); 537 } 538 539 static DEFINE_MUTEX(of_fdt_unflatten_mutex); 540 541 /** 542 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob 543 * @blob: Flat device tree blob 544 * @dad: Parent device node 545 * @mynodes: The device tree created by the call 546 * 547 * unflattens the device-tree passed by the firmware, creating the 548 * tree of struct device_node. It also fills the "name" and "type" 549 * pointers of the nodes so the normal device-tree walking functions 550 * can be used. 551 * 552 * Returns NULL on failure or the memory chunk containing the unflattened 553 * device tree on success. 554 */ 555 void *of_fdt_unflatten_tree(const unsigned long *blob, 556 struct device_node *dad, 557 struct device_node **mynodes) 558 { 559 void *mem; 560 561 mutex_lock(&of_fdt_unflatten_mutex); 562 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc, 563 true); 564 mutex_unlock(&of_fdt_unflatten_mutex); 565 566 return mem; 567 } 568 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree); 569 570 /* Everything below here references initial_boot_params directly. */ 571 int __initdata dt_root_addr_cells; 572 int __initdata dt_root_size_cells; 573 574 void *initial_boot_params; 575 576 #ifdef CONFIG_OF_EARLY_FLATTREE 577 578 static u32 of_fdt_crc32; 579 580 /** 581 * res_mem_reserve_reg() - reserve all memory described in 'reg' property 582 */ 583 static int __init __reserved_mem_reserve_reg(unsigned long node, 584 const char *uname) 585 { 586 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32); 587 phys_addr_t base, size; 588 int len; 589 const __be32 *prop; 590 int nomap, first = 1; 591 592 prop = of_get_flat_dt_prop(node, "reg", &len); 593 if (!prop) 594 return -ENOENT; 595 596 if (len && len % t_len != 0) { 597 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n", 598 uname); 599 return -EINVAL; 600 } 601 602 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL; 603 604 while (len >= t_len) { 605 base = dt_mem_next_cell(dt_root_addr_cells, &prop); 606 size = dt_mem_next_cell(dt_root_size_cells, &prop); 607 608 if (size && 609 early_init_dt_reserve_memory_arch(base, size, nomap) == 0) 610 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n", 611 uname, &base, (unsigned long)size / SZ_1M); 612 else 613 pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n", 614 uname, &base, (unsigned long)size / SZ_1M); 615 616 len -= t_len; 617 if (first) { 618 fdt_reserved_mem_save_node(node, uname, base, size); 619 first = 0; 620 } 621 } 622 return 0; 623 } 624 625 /** 626 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided 627 * in /reserved-memory matches the values supported by the current implementation, 628 * also check if ranges property has been provided 629 */ 630 static int __init __reserved_mem_check_root(unsigned long node) 631 { 632 const __be32 *prop; 633 634 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 635 if (!prop || be32_to_cpup(prop) != dt_root_size_cells) 636 return -EINVAL; 637 638 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 639 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells) 640 return -EINVAL; 641 642 prop = of_get_flat_dt_prop(node, "ranges", NULL); 643 if (!prop) 644 return -EINVAL; 645 return 0; 646 } 647 648 /** 649 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory 650 */ 651 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname, 652 int depth, void *data) 653 { 654 static int found; 655 const char *status; 656 int err; 657 658 if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) { 659 if (__reserved_mem_check_root(node) != 0) { 660 pr_err("Reserved memory: unsupported node format, ignoring\n"); 661 /* break scan */ 662 return 1; 663 } 664 found = 1; 665 /* scan next node */ 666 return 0; 667 } else if (!found) { 668 /* scan next node */ 669 return 0; 670 } else if (found && depth < 2) { 671 /* scanning of /reserved-memory has been finished */ 672 return 1; 673 } 674 675 status = of_get_flat_dt_prop(node, "status", NULL); 676 if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0) 677 return 0; 678 679 err = __reserved_mem_reserve_reg(node, uname); 680 if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL)) 681 fdt_reserved_mem_save_node(node, uname, 0, 0); 682 683 /* scan next node */ 684 return 0; 685 } 686 687 /** 688 * early_init_fdt_scan_reserved_mem() - create reserved memory regions 689 * 690 * This function grabs memory from early allocator for device exclusive use 691 * defined in device tree structures. It should be called by arch specific code 692 * once the early allocator (i.e. memblock) has been fully activated. 693 */ 694 void __init early_init_fdt_scan_reserved_mem(void) 695 { 696 int n; 697 u64 base, size; 698 699 if (!initial_boot_params) 700 return; 701 702 /* Process header /memreserve/ fields */ 703 for (n = 0; ; n++) { 704 fdt_get_mem_rsv(initial_boot_params, n, &base, &size); 705 if (!size) 706 break; 707 early_init_dt_reserve_memory_arch(base, size, 0); 708 } 709 710 of_scan_flat_dt(__fdt_scan_reserved_mem, NULL); 711 fdt_init_reserved_mem(); 712 } 713 714 /** 715 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob 716 */ 717 void __init early_init_fdt_reserve_self(void) 718 { 719 if (!initial_boot_params) 720 return; 721 722 /* Reserve the dtb region */ 723 early_init_dt_reserve_memory_arch(__pa(initial_boot_params), 724 fdt_totalsize(initial_boot_params), 725 0); 726 } 727 728 /** 729 * of_scan_flat_dt - scan flattened tree blob and call callback on each. 730 * @it: callback function 731 * @data: context data pointer 732 * 733 * This function is used to scan the flattened device-tree, it is 734 * used to extract the memory information at boot before we can 735 * unflatten the tree 736 */ 737 int __init of_scan_flat_dt(int (*it)(unsigned long node, 738 const char *uname, int depth, 739 void *data), 740 void *data) 741 { 742 const void *blob = initial_boot_params; 743 const char *pathp; 744 int offset, rc = 0, depth = -1; 745 746 if (!blob) 747 return 0; 748 749 for (offset = fdt_next_node(blob, -1, &depth); 750 offset >= 0 && depth >= 0 && !rc; 751 offset = fdt_next_node(blob, offset, &depth)) { 752 753 pathp = fdt_get_name(blob, offset, NULL); 754 if (*pathp == '/') 755 pathp = kbasename(pathp); 756 rc = it(offset, pathp, depth, data); 757 } 758 return rc; 759 } 760 761 /** 762 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each. 763 * @it: callback function 764 * @data: context data pointer 765 * 766 * This function is used to scan sub-nodes of a node. 767 */ 768 int __init of_scan_flat_dt_subnodes(unsigned long parent, 769 int (*it)(unsigned long node, 770 const char *uname, 771 void *data), 772 void *data) 773 { 774 const void *blob = initial_boot_params; 775 int node; 776 777 fdt_for_each_subnode(node, blob, parent) { 778 const char *pathp; 779 int rc; 780 781 pathp = fdt_get_name(blob, node, NULL); 782 if (*pathp == '/') 783 pathp = kbasename(pathp); 784 rc = it(node, pathp, data); 785 if (rc) 786 return rc; 787 } 788 return 0; 789 } 790 791 /** 792 * of_get_flat_dt_subnode_by_name - get the subnode by given name 793 * 794 * @node: the parent node 795 * @uname: the name of subnode 796 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none 797 */ 798 799 int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) 800 { 801 return fdt_subnode_offset(initial_boot_params, node, uname); 802 } 803 804 /** 805 * of_get_flat_dt_root - find the root node in the flat blob 806 */ 807 unsigned long __init of_get_flat_dt_root(void) 808 { 809 return 0; 810 } 811 812 /** 813 * of_get_flat_dt_size - Return the total size of the FDT 814 */ 815 int __init of_get_flat_dt_size(void) 816 { 817 return fdt_totalsize(initial_boot_params); 818 } 819 820 /** 821 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr 822 * 823 * This function can be used within scan_flattened_dt callback to get 824 * access to properties 825 */ 826 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name, 827 int *size) 828 { 829 return fdt_getprop(initial_boot_params, node, name, size); 830 } 831 832 /** 833 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list 834 * @node: node to test 835 * @compat: compatible string to compare with compatible list. 836 */ 837 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat) 838 { 839 return of_fdt_is_compatible(initial_boot_params, node, compat); 840 } 841 842 /** 843 * of_flat_dt_match - Return true if node matches a list of compatible values 844 */ 845 int __init of_flat_dt_match(unsigned long node, const char *const *compat) 846 { 847 return of_fdt_match(initial_boot_params, node, compat); 848 } 849 850 /** 851 * of_get_flat_dt_prop - Given a node in the flat blob, return the phandle 852 */ 853 uint32_t __init of_get_flat_dt_phandle(unsigned long node) 854 { 855 return fdt_get_phandle(initial_boot_params, node); 856 } 857 858 struct fdt_scan_status { 859 const char *name; 860 int namelen; 861 int depth; 862 int found; 863 int (*iterator)(unsigned long node, const char *uname, int depth, void *data); 864 void *data; 865 }; 866 867 const char * __init of_flat_dt_get_machine_name(void) 868 { 869 const char *name; 870 unsigned long dt_root = of_get_flat_dt_root(); 871 872 name = of_get_flat_dt_prop(dt_root, "model", NULL); 873 if (!name) 874 name = of_get_flat_dt_prop(dt_root, "compatible", NULL); 875 return name; 876 } 877 878 /** 879 * of_flat_dt_match_machine - Iterate match tables to find matching machine. 880 * 881 * @default_match: A machine specific ptr to return in case of no match. 882 * @get_next_compat: callback function to return next compatible match table. 883 * 884 * Iterate through machine match tables to find the best match for the machine 885 * compatible string in the FDT. 886 */ 887 const void * __init of_flat_dt_match_machine(const void *default_match, 888 const void * (*get_next_compat)(const char * const**)) 889 { 890 const void *data = NULL; 891 const void *best_data = default_match; 892 const char *const *compat; 893 unsigned long dt_root; 894 unsigned int best_score = ~1, score = 0; 895 896 dt_root = of_get_flat_dt_root(); 897 while ((data = get_next_compat(&compat))) { 898 score = of_flat_dt_match(dt_root, compat); 899 if (score > 0 && score < best_score) { 900 best_data = data; 901 best_score = score; 902 } 903 } 904 if (!best_data) { 905 const char *prop; 906 int size; 907 908 pr_err("\n unrecognized device tree list:\n[ "); 909 910 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 911 if (prop) { 912 while (size > 0) { 913 printk("'%s' ", prop); 914 size -= strlen(prop) + 1; 915 prop += strlen(prop) + 1; 916 } 917 } 918 printk("]\n\n"); 919 return NULL; 920 } 921 922 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name()); 923 924 return best_data; 925 } 926 927 #ifdef CONFIG_BLK_DEV_INITRD 928 #ifndef __early_init_dt_declare_initrd 929 static void __early_init_dt_declare_initrd(unsigned long start, 930 unsigned long end) 931 { 932 initrd_start = (unsigned long)__va(start); 933 initrd_end = (unsigned long)__va(end); 934 initrd_below_start_ok = 1; 935 } 936 #endif 937 938 /** 939 * early_init_dt_check_for_initrd - Decode initrd location from flat tree 940 * @node: reference to node containing initrd location ('chosen') 941 */ 942 static void __init early_init_dt_check_for_initrd(unsigned long node) 943 { 944 u64 start, end; 945 int len; 946 const __be32 *prop; 947 948 pr_debug("Looking for initrd properties... "); 949 950 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len); 951 if (!prop) 952 return; 953 start = of_read_number(prop, len/4); 954 955 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len); 956 if (!prop) 957 return; 958 end = of_read_number(prop, len/4); 959 960 __early_init_dt_declare_initrd(start, end); 961 962 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", 963 (unsigned long long)start, (unsigned long long)end); 964 } 965 #else 966 static inline void early_init_dt_check_for_initrd(unsigned long node) 967 { 968 } 969 #endif /* CONFIG_BLK_DEV_INITRD */ 970 971 #ifdef CONFIG_SERIAL_EARLYCON 972 973 int __init early_init_dt_scan_chosen_stdout(void) 974 { 975 int offset; 976 const char *p, *q, *options = NULL; 977 int l; 978 const struct earlycon_id *match; 979 const void *fdt = initial_boot_params; 980 981 offset = fdt_path_offset(fdt, "/chosen"); 982 if (offset < 0) 983 offset = fdt_path_offset(fdt, "/chosen@0"); 984 if (offset < 0) 985 return -ENOENT; 986 987 p = fdt_getprop(fdt, offset, "stdout-path", &l); 988 if (!p) 989 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l); 990 if (!p || !l) 991 return -ENOENT; 992 993 q = strchrnul(p, ':'); 994 if (*q != '\0') 995 options = q + 1; 996 l = q - p; 997 998 /* Get the node specified by stdout-path */ 999 offset = fdt_path_offset_namelen(fdt, p, l); 1000 if (offset < 0) { 1001 pr_warn("earlycon: stdout-path %.*s not found\n", l, p); 1002 return 0; 1003 } 1004 1005 for (match = __earlycon_table; match < __earlycon_table_end; match++) { 1006 if (!match->compatible[0]) 1007 continue; 1008 1009 if (fdt_node_check_compatible(fdt, offset, match->compatible)) 1010 continue; 1011 1012 of_setup_earlycon(match, offset, options); 1013 return 0; 1014 } 1015 return -ENODEV; 1016 } 1017 #endif 1018 1019 /** 1020 * early_init_dt_scan_root - fetch the top level address and size cells 1021 */ 1022 int __init early_init_dt_scan_root(unsigned long node, const char *uname, 1023 int depth, void *data) 1024 { 1025 const __be32 *prop; 1026 1027 if (depth != 0) 1028 return 0; 1029 1030 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 1031 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 1032 1033 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 1034 if (prop) 1035 dt_root_size_cells = be32_to_cpup(prop); 1036 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells); 1037 1038 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 1039 if (prop) 1040 dt_root_addr_cells = be32_to_cpup(prop); 1041 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells); 1042 1043 /* break now */ 1044 return 1; 1045 } 1046 1047 u64 __init dt_mem_next_cell(int s, const __be32 **cellp) 1048 { 1049 const __be32 *p = *cellp; 1050 1051 *cellp = p + s; 1052 return of_read_number(p, s); 1053 } 1054 1055 /** 1056 * early_init_dt_scan_memory - Look for and parse memory nodes 1057 */ 1058 int __init early_init_dt_scan_memory(unsigned long node, const char *uname, 1059 int depth, void *data) 1060 { 1061 const char *type = of_get_flat_dt_prop(node, "device_type", NULL); 1062 const __be32 *reg, *endp; 1063 int l; 1064 bool hotpluggable; 1065 1066 /* We are scanning "memory" nodes only */ 1067 if (type == NULL) { 1068 /* 1069 * The longtrail doesn't have a device_type on the 1070 * /memory node, so look for the node called /memory@0. 1071 */ 1072 if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0) 1073 return 0; 1074 } else if (strcmp(type, "memory") != 0) 1075 return 0; 1076 1077 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l); 1078 if (reg == NULL) 1079 reg = of_get_flat_dt_prop(node, "reg", &l); 1080 if (reg == NULL) 1081 return 0; 1082 1083 endp = reg + (l / sizeof(__be32)); 1084 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL); 1085 1086 pr_debug("memory scan node %s, reg size %d,\n", uname, l); 1087 1088 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) { 1089 u64 base, size; 1090 1091 base = dt_mem_next_cell(dt_root_addr_cells, ®); 1092 size = dt_mem_next_cell(dt_root_size_cells, ®); 1093 1094 if (size == 0) 1095 continue; 1096 pr_debug(" - %llx , %llx\n", (unsigned long long)base, 1097 (unsigned long long)size); 1098 1099 early_init_dt_add_memory_arch(base, size); 1100 1101 if (!hotpluggable) 1102 continue; 1103 1104 if (early_init_dt_mark_hotplug_memory_arch(base, size)) 1105 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n", 1106 base, base + size); 1107 } 1108 1109 return 0; 1110 } 1111 1112 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, 1113 int depth, void *data) 1114 { 1115 int l; 1116 const char *p; 1117 1118 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); 1119 1120 if (depth != 1 || !data || 1121 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0)) 1122 return 0; 1123 1124 early_init_dt_check_for_initrd(node); 1125 1126 /* Retrieve command line */ 1127 p = of_get_flat_dt_prop(node, "bootargs", &l); 1128 if (p != NULL && l > 0) 1129 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE)); 1130 1131 /* 1132 * CONFIG_CMDLINE is meant to be a default in case nothing else 1133 * managed to set the command line, unless CONFIG_CMDLINE_FORCE 1134 * is set in which case we override whatever was found earlier. 1135 */ 1136 #ifdef CONFIG_CMDLINE 1137 #if defined(CONFIG_CMDLINE_EXTEND) 1138 strlcat(data, " ", COMMAND_LINE_SIZE); 1139 strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1140 #elif defined(CONFIG_CMDLINE_FORCE) 1141 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1142 #else 1143 /* No arguments from boot loader, use kernel's cmdl*/ 1144 if (!((char *)data)[0]) 1145 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1146 #endif 1147 #endif /* CONFIG_CMDLINE */ 1148 1149 pr_debug("Command line is: %s\n", (char*)data); 1150 1151 /* break now */ 1152 return 1; 1153 } 1154 1155 #ifdef CONFIG_HAVE_MEMBLOCK 1156 #ifndef MIN_MEMBLOCK_ADDR 1157 #define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET) 1158 #endif 1159 #ifndef MAX_MEMBLOCK_ADDR 1160 #define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0) 1161 #endif 1162 1163 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) 1164 { 1165 const u64 phys_offset = MIN_MEMBLOCK_ADDR; 1166 1167 if (!PAGE_ALIGNED(base)) { 1168 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { 1169 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1170 base, base + size); 1171 return; 1172 } 1173 size -= PAGE_SIZE - (base & ~PAGE_MASK); 1174 base = PAGE_ALIGN(base); 1175 } 1176 size &= PAGE_MASK; 1177 1178 if (base > MAX_MEMBLOCK_ADDR) { 1179 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n", 1180 base, base + size); 1181 return; 1182 } 1183 1184 if (base + size - 1 > MAX_MEMBLOCK_ADDR) { 1185 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n", 1186 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size); 1187 size = MAX_MEMBLOCK_ADDR - base + 1; 1188 } 1189 1190 if (base + size < phys_offset) { 1191 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n", 1192 base, base + size); 1193 return; 1194 } 1195 if (base < phys_offset) { 1196 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n", 1197 base, phys_offset); 1198 size -= phys_offset - base; 1199 base = phys_offset; 1200 } 1201 memblock_add(base, size); 1202 } 1203 1204 int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size) 1205 { 1206 return memblock_mark_hotplug(base, size); 1207 } 1208 1209 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base, 1210 phys_addr_t size, bool nomap) 1211 { 1212 if (nomap) 1213 return memblock_remove(base, size); 1214 return memblock_reserve(base, size); 1215 } 1216 1217 /* 1218 * called from unflatten_device_tree() to bootstrap devicetree itself 1219 * Architectures can override this definition if memblock isn't used 1220 */ 1221 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align) 1222 { 1223 return __va(memblock_alloc(size, align)); 1224 } 1225 #else 1226 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) 1227 { 1228 WARN_ON(1); 1229 } 1230 1231 int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size) 1232 { 1233 return -ENOSYS; 1234 } 1235 1236 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base, 1237 phys_addr_t size, bool nomap) 1238 { 1239 pr_err("Reserved memory not supported, ignoring range %pa - %pa%s\n", 1240 &base, &size, nomap ? " (nomap)" : ""); 1241 return -ENOSYS; 1242 } 1243 1244 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align) 1245 { 1246 WARN_ON(1); 1247 return NULL; 1248 } 1249 #endif 1250 1251 bool __init early_init_dt_verify(void *params) 1252 { 1253 if (!params) 1254 return false; 1255 1256 /* check device tree validity */ 1257 if (fdt_check_header(params)) 1258 return false; 1259 1260 /* Setup flat device-tree pointer */ 1261 initial_boot_params = params; 1262 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1263 fdt_totalsize(initial_boot_params)); 1264 return true; 1265 } 1266 1267 1268 void __init early_init_dt_scan_nodes(void) 1269 { 1270 /* Retrieve various information from the /chosen node */ 1271 of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); 1272 1273 /* Initialize {size,address}-cells info */ 1274 of_scan_flat_dt(early_init_dt_scan_root, NULL); 1275 1276 /* Setup memory, calling early_init_dt_add_memory_arch */ 1277 of_scan_flat_dt(early_init_dt_scan_memory, NULL); 1278 } 1279 1280 bool __init early_init_dt_scan(void *params) 1281 { 1282 bool status; 1283 1284 status = early_init_dt_verify(params); 1285 if (!status) 1286 return false; 1287 1288 early_init_dt_scan_nodes(); 1289 return true; 1290 } 1291 1292 /** 1293 * unflatten_device_tree - create tree of device_nodes from flat blob 1294 * 1295 * unflattens the device-tree passed by the firmware, creating the 1296 * tree of struct device_node. It also fills the "name" and "type" 1297 * pointers of the nodes so the normal device-tree walking functions 1298 * can be used. 1299 */ 1300 void __init unflatten_device_tree(void) 1301 { 1302 __unflatten_device_tree(initial_boot_params, NULL, &of_root, 1303 early_init_dt_alloc_memory_arch, false); 1304 1305 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ 1306 of_alias_scan(early_init_dt_alloc_memory_arch); 1307 1308 unittest_unflatten_overlay_base(); 1309 } 1310 1311 /** 1312 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob 1313 * 1314 * Copies and unflattens the device-tree passed by the firmware, creating the 1315 * tree of struct device_node. It also fills the "name" and "type" 1316 * pointers of the nodes so the normal device-tree walking functions 1317 * can be used. This should only be used when the FDT memory has not been 1318 * reserved such is the case when the FDT is built-in to the kernel init 1319 * section. If the FDT memory is reserved already then unflatten_device_tree 1320 * should be used instead. 1321 */ 1322 void __init unflatten_and_copy_device_tree(void) 1323 { 1324 int size; 1325 void *dt; 1326 1327 if (!initial_boot_params) { 1328 pr_warn("No valid device tree found, continuing without\n"); 1329 return; 1330 } 1331 1332 size = fdt_totalsize(initial_boot_params); 1333 dt = early_init_dt_alloc_memory_arch(size, 1334 roundup_pow_of_two(FDT_V17_SIZE)); 1335 1336 if (dt) { 1337 memcpy(dt, initial_boot_params, size); 1338 initial_boot_params = dt; 1339 } 1340 unflatten_device_tree(); 1341 } 1342 1343 #ifdef CONFIG_SYSFS 1344 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj, 1345 struct bin_attribute *bin_attr, 1346 char *buf, loff_t off, size_t count) 1347 { 1348 memcpy(buf, initial_boot_params + off, count); 1349 return count; 1350 } 1351 1352 static int __init of_fdt_raw_init(void) 1353 { 1354 static struct bin_attribute of_fdt_raw_attr = 1355 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0); 1356 1357 if (!initial_boot_params) 1358 return 0; 1359 1360 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params, 1361 fdt_totalsize(initial_boot_params))) { 1362 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n"); 1363 return 0; 1364 } 1365 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params); 1366 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr); 1367 } 1368 late_initcall(of_fdt_raw_init); 1369 #endif 1370 1371 #endif /* CONFIG_OF_EARLY_FLATTREE */ 1372