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 /* 35 * of_fdt_limit_memory - limit the number of regions in the /memory node 36 * @limit: maximum entries 37 * 38 * Adjust the flattened device tree to have at most 'limit' number of 39 * memory entries in the /memory node. This function may be called 40 * any time after initial_boot_param is set. 41 */ 42 void of_fdt_limit_memory(int limit) 43 { 44 int memory; 45 int len; 46 const void *val; 47 int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 48 int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 49 const uint32_t *addr_prop; 50 const uint32_t *size_prop; 51 int root_offset; 52 int cell_size; 53 54 root_offset = fdt_path_offset(initial_boot_params, "/"); 55 if (root_offset < 0) 56 return; 57 58 addr_prop = fdt_getprop(initial_boot_params, root_offset, 59 "#address-cells", NULL); 60 if (addr_prop) 61 nr_address_cells = fdt32_to_cpu(*addr_prop); 62 63 size_prop = fdt_getprop(initial_boot_params, root_offset, 64 "#size-cells", NULL); 65 if (size_prop) 66 nr_size_cells = fdt32_to_cpu(*size_prop); 67 68 cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells); 69 70 memory = fdt_path_offset(initial_boot_params, "/memory"); 71 if (memory > 0) { 72 val = fdt_getprop(initial_boot_params, memory, "reg", &len); 73 if (len > limit*cell_size) { 74 len = limit*cell_size; 75 pr_debug("Limiting number of entries to %d\n", limit); 76 fdt_setprop(initial_boot_params, memory, "reg", val, 77 len); 78 } 79 } 80 } 81 82 /** 83 * of_fdt_is_compatible - Return true if given node from the given blob has 84 * compat in its compatible list 85 * @blob: A device tree blob 86 * @node: node to test 87 * @compat: compatible string to compare with compatible list. 88 * 89 * On match, returns a non-zero value with smaller values returned for more 90 * specific compatible values. 91 */ 92 int of_fdt_is_compatible(const void *blob, 93 unsigned long node, const char *compat) 94 { 95 const char *cp; 96 int cplen; 97 unsigned long l, score = 0; 98 99 cp = fdt_getprop(blob, node, "compatible", &cplen); 100 if (cp == NULL) 101 return 0; 102 while (cplen > 0) { 103 score++; 104 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) 105 return score; 106 l = strlen(cp) + 1; 107 cp += l; 108 cplen -= l; 109 } 110 111 return 0; 112 } 113 114 /** 115 * of_fdt_is_big_endian - Return true if given node needs BE MMIO accesses 116 * @blob: A device tree blob 117 * @node: node to test 118 * 119 * Returns true if the node has a "big-endian" property, or if the kernel 120 * was compiled for BE *and* the node has a "native-endian" property. 121 * Returns false otherwise. 122 */ 123 bool of_fdt_is_big_endian(const void *blob, unsigned long node) 124 { 125 if (fdt_getprop(blob, node, "big-endian", NULL)) 126 return true; 127 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) && 128 fdt_getprop(blob, node, "native-endian", NULL)) 129 return true; 130 return false; 131 } 132 133 /** 134 * of_fdt_match - Return true if node matches a list of compatible values 135 */ 136 int of_fdt_match(const void *blob, unsigned long node, 137 const char *const *compat) 138 { 139 unsigned int tmp, score = 0; 140 141 if (!compat) 142 return 0; 143 144 while (*compat) { 145 tmp = of_fdt_is_compatible(blob, node, *compat); 146 if (tmp && (score == 0 || (tmp < score))) 147 score = tmp; 148 compat++; 149 } 150 151 return score; 152 } 153 154 static void *unflatten_dt_alloc(void **mem, unsigned long size, 155 unsigned long align) 156 { 157 void *res; 158 159 *mem = PTR_ALIGN(*mem, align); 160 res = *mem; 161 *mem += size; 162 163 return res; 164 } 165 166 static void populate_properties(const void *blob, 167 int offset, 168 void **mem, 169 struct device_node *np, 170 const char *nodename, 171 bool dryrun) 172 { 173 struct property *pp, **pprev = NULL; 174 int cur; 175 bool has_name = false; 176 177 pprev = &np->properties; 178 for (cur = fdt_first_property_offset(blob, offset); 179 cur >= 0; 180 cur = fdt_next_property_offset(blob, cur)) { 181 const __be32 *val; 182 const char *pname; 183 u32 sz; 184 185 val = fdt_getprop_by_offset(blob, cur, &pname, &sz); 186 if (!val) { 187 pr_warn("Cannot locate property at 0x%x\n", cur); 188 continue; 189 } 190 191 if (!pname) { 192 pr_warn("Cannot find property name at 0x%x\n", cur); 193 continue; 194 } 195 196 if (!strcmp(pname, "name")) 197 has_name = true; 198 199 pp = unflatten_dt_alloc(mem, sizeof(struct property), 200 __alignof__(struct property)); 201 if (dryrun) 202 continue; 203 204 /* We accept flattened tree phandles either in 205 * ePAPR-style "phandle" properties, or the 206 * legacy "linux,phandle" properties. If both 207 * appear and have different values, things 208 * will get weird. Don't do that. 209 */ 210 if (!strcmp(pname, "phandle") || 211 !strcmp(pname, "linux,phandle")) { 212 if (!np->phandle) 213 np->phandle = be32_to_cpup(val); 214 } 215 216 /* And we process the "ibm,phandle" property 217 * used in pSeries dynamic device tree 218 * stuff 219 */ 220 if (!strcmp(pname, "ibm,phandle")) 221 np->phandle = be32_to_cpup(val); 222 223 pp->name = (char *)pname; 224 pp->length = sz; 225 pp->value = (__be32 *)val; 226 *pprev = pp; 227 pprev = &pp->next; 228 } 229 230 /* With version 0x10 we may not have the name property, 231 * recreate it here from the unit name if absent 232 */ 233 if (!has_name) { 234 const char *p = nodename, *ps = p, *pa = NULL; 235 int len; 236 237 while (*p) { 238 if ((*p) == '@') 239 pa = p; 240 else if ((*p) == '/') 241 ps = p + 1; 242 p++; 243 } 244 245 if (pa < ps) 246 pa = p; 247 len = (pa - ps) + 1; 248 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len, 249 __alignof__(struct property)); 250 if (!dryrun) { 251 pp->name = "name"; 252 pp->length = len; 253 pp->value = pp + 1; 254 *pprev = pp; 255 pprev = &pp->next; 256 memcpy(pp->value, ps, len - 1); 257 ((char *)pp->value)[len - 1] = 0; 258 pr_debug("fixed up name for %s -> %s\n", 259 nodename, (char *)pp->value); 260 } 261 } 262 263 if (!dryrun) 264 *pprev = NULL; 265 } 266 267 static unsigned int populate_node(const void *blob, 268 int offset, 269 void **mem, 270 struct device_node *dad, 271 unsigned int fpsize, 272 struct device_node **pnp, 273 bool dryrun) 274 { 275 struct device_node *np; 276 const char *pathp; 277 unsigned int l, allocl; 278 int new_format = 0; 279 280 pathp = fdt_get_name(blob, offset, &l); 281 if (!pathp) { 282 *pnp = NULL; 283 return 0; 284 } 285 286 allocl = ++l; 287 288 /* version 0x10 has a more compact unit name here instead of the full 289 * path. we accumulate the full path size using "fpsize", we'll rebuild 290 * it later. We detect this because the first character of the name is 291 * not '/'. 292 */ 293 if ((*pathp) != '/') { 294 new_format = 1; 295 if (fpsize == 0) { 296 /* root node: special case. fpsize accounts for path 297 * plus terminating zero. root node only has '/', so 298 * fpsize should be 2, but we want to avoid the first 299 * level nodes to have two '/' so we use fpsize 1 here 300 */ 301 fpsize = 1; 302 allocl = 2; 303 l = 1; 304 pathp = ""; 305 } else { 306 /* account for '/' and path size minus terminal 0 307 * already in 'l' 308 */ 309 fpsize += l; 310 allocl = fpsize; 311 } 312 } 313 314 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl, 315 __alignof__(struct device_node)); 316 if (!dryrun) { 317 char *fn; 318 of_node_init(np); 319 np->full_name = fn = ((char *)np) + sizeof(*np); 320 if (new_format) { 321 /* rebuild full path for new format */ 322 if (dad && dad->parent) { 323 strcpy(fn, dad->full_name); 324 #ifdef DEBUG 325 if ((strlen(fn) + l + 1) != allocl) { 326 pr_debug("%s: p: %d, l: %d, a: %d\n", 327 pathp, (int)strlen(fn), 328 l, allocl); 329 } 330 #endif 331 fn += strlen(fn); 332 } 333 *(fn++) = '/'; 334 } 335 memcpy(fn, pathp, l); 336 337 if (dad != NULL) { 338 np->parent = dad; 339 np->sibling = dad->child; 340 dad->child = np; 341 } 342 } 343 344 populate_properties(blob, offset, mem, np, pathp, dryrun); 345 if (!dryrun) { 346 np->name = of_get_property(np, "name", NULL); 347 np->type = of_get_property(np, "device_type", NULL); 348 349 if (!np->name) 350 np->name = "<NULL>"; 351 if (!np->type) 352 np->type = "<NULL>"; 353 } 354 355 *pnp = np; 356 return fpsize; 357 } 358 359 static void reverse_nodes(struct device_node *parent) 360 { 361 struct device_node *child, *next; 362 363 /* In-depth first */ 364 child = parent->child; 365 while (child) { 366 reverse_nodes(child); 367 368 child = child->sibling; 369 } 370 371 /* Reverse the nodes in the child list */ 372 child = parent->child; 373 parent->child = NULL; 374 while (child) { 375 next = child->sibling; 376 377 child->sibling = parent->child; 378 parent->child = child; 379 child = next; 380 } 381 } 382 383 /** 384 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree 385 * @blob: The parent device tree blob 386 * @mem: Memory chunk to use for allocating device nodes and properties 387 * @dad: Parent struct device_node 388 * @nodepp: The device_node tree created by the call 389 * 390 * It returns the size of unflattened device tree or error code 391 */ 392 static int unflatten_dt_nodes(const void *blob, 393 void *mem, 394 struct device_node *dad, 395 struct device_node **nodepp) 396 { 397 struct device_node *root; 398 int offset = 0, depth = 0, initial_depth = 0; 399 #define FDT_MAX_DEPTH 64 400 unsigned int fpsizes[FDT_MAX_DEPTH]; 401 struct device_node *nps[FDT_MAX_DEPTH]; 402 void *base = mem; 403 bool dryrun = !base; 404 405 if (nodepp) 406 *nodepp = NULL; 407 408 /* 409 * We're unflattening device sub-tree if @dad is valid. There are 410 * possibly multiple nodes in the first level of depth. We need 411 * set @depth to 1 to make fdt_next_node() happy as it bails 412 * immediately when negative @depth is found. Otherwise, the device 413 * nodes except the first one won't be unflattened successfully. 414 */ 415 if (dad) 416 depth = initial_depth = 1; 417 418 root = dad; 419 fpsizes[depth] = dad ? strlen(of_node_full_name(dad)) : 0; 420 nps[depth] = dad; 421 422 for (offset = 0; 423 offset >= 0 && depth >= initial_depth; 424 offset = fdt_next_node(blob, offset, &depth)) { 425 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH)) 426 continue; 427 428 fpsizes[depth+1] = populate_node(blob, offset, &mem, 429 nps[depth], 430 fpsizes[depth], 431 &nps[depth+1], dryrun); 432 if (!fpsizes[depth+1]) 433 return mem - base; 434 435 if (!dryrun && nodepp && !*nodepp) 436 *nodepp = nps[depth+1]; 437 if (!dryrun && !root) 438 root = nps[depth+1]; 439 } 440 441 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) { 442 pr_err("Error %d processing FDT\n", offset); 443 return -EINVAL; 444 } 445 446 /* 447 * Reverse the child list. Some drivers assumes node order matches .dts 448 * node order 449 */ 450 if (!dryrun) 451 reverse_nodes(root); 452 453 return mem - base; 454 } 455 456 /** 457 * __unflatten_device_tree - create tree of device_nodes from flat blob 458 * 459 * unflattens a device-tree, creating the 460 * tree of struct device_node. It also fills the "name" and "type" 461 * pointers of the nodes so the normal device-tree walking functions 462 * can be used. 463 * @blob: The blob to expand 464 * @dad: Parent device node 465 * @mynodes: The device_node tree created by the call 466 * @dt_alloc: An allocator that provides a virtual address to memory 467 * for the resulting tree 468 * 469 * Returns NULL on failure or the memory chunk containing the unflattened 470 * device tree on success. 471 */ 472 static void *__unflatten_device_tree(const void *blob, 473 struct device_node *dad, 474 struct device_node **mynodes, 475 void *(*dt_alloc)(u64 size, u64 align), 476 bool detached) 477 { 478 int size; 479 void *mem; 480 481 pr_debug(" -> unflatten_device_tree()\n"); 482 483 if (!blob) { 484 pr_debug("No device tree pointer\n"); 485 return NULL; 486 } 487 488 pr_debug("Unflattening device tree:\n"); 489 pr_debug("magic: %08x\n", fdt_magic(blob)); 490 pr_debug("size: %08x\n", fdt_totalsize(blob)); 491 pr_debug("version: %08x\n", fdt_version(blob)); 492 493 if (fdt_check_header(blob)) { 494 pr_err("Invalid device tree blob header\n"); 495 return NULL; 496 } 497 498 /* First pass, scan for size */ 499 size = unflatten_dt_nodes(blob, NULL, dad, NULL); 500 if (size < 0) 501 return NULL; 502 503 size = ALIGN(size, 4); 504 pr_debug(" size is %d, allocating...\n", size); 505 506 /* Allocate memory for the expanded device tree */ 507 mem = dt_alloc(size + 4, __alignof__(struct device_node)); 508 memset(mem, 0, size); 509 510 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef); 511 512 pr_debug(" unflattening %p...\n", mem); 513 514 /* Second pass, do actual unflattening */ 515 unflatten_dt_nodes(blob, mem, dad, mynodes); 516 if (be32_to_cpup(mem + size) != 0xdeadbeef) 517 pr_warning("End of tree marker overwritten: %08x\n", 518 be32_to_cpup(mem + size)); 519 520 if (detached && mynodes) { 521 of_node_set_flag(*mynodes, OF_DETACHED); 522 pr_debug("unflattened tree is detached\n"); 523 } 524 525 pr_debug(" <- unflatten_device_tree()\n"); 526 return mem; 527 } 528 529 static void *kernel_tree_alloc(u64 size, u64 align) 530 { 531 return kzalloc(size, GFP_KERNEL); 532 } 533 534 static DEFINE_MUTEX(of_fdt_unflatten_mutex); 535 536 /** 537 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob 538 * @blob: Flat device tree blob 539 * @dad: Parent device node 540 * @mynodes: The device tree created by the call 541 * 542 * unflattens the device-tree passed by the firmware, creating the 543 * tree of struct device_node. It also fills the "name" and "type" 544 * pointers of the nodes so the normal device-tree walking functions 545 * can be used. 546 * 547 * Returns NULL on failure or the memory chunk containing the unflattened 548 * device tree on success. 549 */ 550 void *of_fdt_unflatten_tree(const unsigned long *blob, 551 struct device_node *dad, 552 struct device_node **mynodes) 553 { 554 void *mem; 555 556 mutex_lock(&of_fdt_unflatten_mutex); 557 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc, 558 true); 559 mutex_unlock(&of_fdt_unflatten_mutex); 560 561 return mem; 562 } 563 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree); 564 565 /* Everything below here references initial_boot_params directly. */ 566 int __initdata dt_root_addr_cells; 567 int __initdata dt_root_size_cells; 568 569 void *initial_boot_params; 570 571 #ifdef CONFIG_OF_EARLY_FLATTREE 572 573 static u32 of_fdt_crc32; 574 575 /** 576 * res_mem_reserve_reg() - reserve all memory described in 'reg' property 577 */ 578 static int __init __reserved_mem_reserve_reg(unsigned long node, 579 const char *uname) 580 { 581 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32); 582 phys_addr_t base, size; 583 int len; 584 const __be32 *prop; 585 int nomap, first = 1; 586 587 prop = of_get_flat_dt_prop(node, "reg", &len); 588 if (!prop) 589 return -ENOENT; 590 591 if (len && len % t_len != 0) { 592 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n", 593 uname); 594 return -EINVAL; 595 } 596 597 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL; 598 599 while (len >= t_len) { 600 base = dt_mem_next_cell(dt_root_addr_cells, &prop); 601 size = dt_mem_next_cell(dt_root_size_cells, &prop); 602 603 if (size && 604 early_init_dt_reserve_memory_arch(base, size, nomap) == 0) 605 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n", 606 uname, &base, (unsigned long)size / SZ_1M); 607 else 608 pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n", 609 uname, &base, (unsigned long)size / SZ_1M); 610 611 len -= t_len; 612 if (first) { 613 fdt_reserved_mem_save_node(node, uname, base, size); 614 first = 0; 615 } 616 } 617 return 0; 618 } 619 620 /** 621 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided 622 * in /reserved-memory matches the values supported by the current implementation, 623 * also check if ranges property has been provided 624 */ 625 static int __init __reserved_mem_check_root(unsigned long node) 626 { 627 const __be32 *prop; 628 629 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 630 if (!prop || be32_to_cpup(prop) != dt_root_size_cells) 631 return -EINVAL; 632 633 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 634 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells) 635 return -EINVAL; 636 637 prop = of_get_flat_dt_prop(node, "ranges", NULL); 638 if (!prop) 639 return -EINVAL; 640 return 0; 641 } 642 643 /** 644 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory 645 */ 646 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname, 647 int depth, void *data) 648 { 649 static int found; 650 const char *status; 651 int err; 652 653 if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) { 654 if (__reserved_mem_check_root(node) != 0) { 655 pr_err("Reserved memory: unsupported node format, ignoring\n"); 656 /* break scan */ 657 return 1; 658 } 659 found = 1; 660 /* scan next node */ 661 return 0; 662 } else if (!found) { 663 /* scan next node */ 664 return 0; 665 } else if (found && depth < 2) { 666 /* scanning of /reserved-memory has been finished */ 667 return 1; 668 } 669 670 status = of_get_flat_dt_prop(node, "status", NULL); 671 if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0) 672 return 0; 673 674 err = __reserved_mem_reserve_reg(node, uname); 675 if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL)) 676 fdt_reserved_mem_save_node(node, uname, 0, 0); 677 678 /* scan next node */ 679 return 0; 680 } 681 682 /** 683 * early_init_fdt_scan_reserved_mem() - create reserved memory regions 684 * 685 * This function grabs memory from early allocator for device exclusive use 686 * defined in device tree structures. It should be called by arch specific code 687 * once the early allocator (i.e. memblock) has been fully activated. 688 */ 689 void __init early_init_fdt_scan_reserved_mem(void) 690 { 691 int n; 692 u64 base, size; 693 694 if (!initial_boot_params) 695 return; 696 697 /* Process header /memreserve/ fields */ 698 for (n = 0; ; n++) { 699 fdt_get_mem_rsv(initial_boot_params, n, &base, &size); 700 if (!size) 701 break; 702 early_init_dt_reserve_memory_arch(base, size, 0); 703 } 704 705 of_scan_flat_dt(__fdt_scan_reserved_mem, NULL); 706 fdt_init_reserved_mem(); 707 } 708 709 /** 710 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob 711 */ 712 void __init early_init_fdt_reserve_self(void) 713 { 714 if (!initial_boot_params) 715 return; 716 717 /* Reserve the dtb region */ 718 early_init_dt_reserve_memory_arch(__pa(initial_boot_params), 719 fdt_totalsize(initial_boot_params), 720 0); 721 } 722 723 /** 724 * of_scan_flat_dt - scan flattened tree blob and call callback on each. 725 * @it: callback function 726 * @data: context data pointer 727 * 728 * This function is used to scan the flattened device-tree, it is 729 * used to extract the memory information at boot before we can 730 * unflatten the tree 731 */ 732 int __init of_scan_flat_dt(int (*it)(unsigned long node, 733 const char *uname, int depth, 734 void *data), 735 void *data) 736 { 737 const void *blob = initial_boot_params; 738 const char *pathp; 739 int offset, rc = 0, depth = -1; 740 741 for (offset = fdt_next_node(blob, -1, &depth); 742 offset >= 0 && depth >= 0 && !rc; 743 offset = fdt_next_node(blob, offset, &depth)) { 744 745 pathp = fdt_get_name(blob, offset, NULL); 746 if (*pathp == '/') 747 pathp = kbasename(pathp); 748 rc = it(offset, pathp, depth, data); 749 } 750 return rc; 751 } 752 753 /** 754 * of_get_flat_dt_subnode_by_name - get the subnode by given name 755 * 756 * @node: the parent node 757 * @uname: the name of subnode 758 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none 759 */ 760 761 int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) 762 { 763 return fdt_subnode_offset(initial_boot_params, node, uname); 764 } 765 766 /** 767 * of_get_flat_dt_root - find the root node in the flat blob 768 */ 769 unsigned long __init of_get_flat_dt_root(void) 770 { 771 return 0; 772 } 773 774 /** 775 * of_get_flat_dt_size - Return the total size of the FDT 776 */ 777 int __init of_get_flat_dt_size(void) 778 { 779 return fdt_totalsize(initial_boot_params); 780 } 781 782 /** 783 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr 784 * 785 * This function can be used within scan_flattened_dt callback to get 786 * access to properties 787 */ 788 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name, 789 int *size) 790 { 791 return fdt_getprop(initial_boot_params, node, name, size); 792 } 793 794 /** 795 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list 796 * @node: node to test 797 * @compat: compatible string to compare with compatible list. 798 */ 799 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat) 800 { 801 return of_fdt_is_compatible(initial_boot_params, node, compat); 802 } 803 804 /** 805 * of_flat_dt_match - Return true if node matches a list of compatible values 806 */ 807 int __init of_flat_dt_match(unsigned long node, const char *const *compat) 808 { 809 return of_fdt_match(initial_boot_params, node, compat); 810 } 811 812 struct fdt_scan_status { 813 const char *name; 814 int namelen; 815 int depth; 816 int found; 817 int (*iterator)(unsigned long node, const char *uname, int depth, void *data); 818 void *data; 819 }; 820 821 const char * __init of_flat_dt_get_machine_name(void) 822 { 823 const char *name; 824 unsigned long dt_root = of_get_flat_dt_root(); 825 826 name = of_get_flat_dt_prop(dt_root, "model", NULL); 827 if (!name) 828 name = of_get_flat_dt_prop(dt_root, "compatible", NULL); 829 return name; 830 } 831 832 /** 833 * of_flat_dt_match_machine - Iterate match tables to find matching machine. 834 * 835 * @default_match: A machine specific ptr to return in case of no match. 836 * @get_next_compat: callback function to return next compatible match table. 837 * 838 * Iterate through machine match tables to find the best match for the machine 839 * compatible string in the FDT. 840 */ 841 const void * __init of_flat_dt_match_machine(const void *default_match, 842 const void * (*get_next_compat)(const char * const**)) 843 { 844 const void *data = NULL; 845 const void *best_data = default_match; 846 const char *const *compat; 847 unsigned long dt_root; 848 unsigned int best_score = ~1, score = 0; 849 850 dt_root = of_get_flat_dt_root(); 851 while ((data = get_next_compat(&compat))) { 852 score = of_flat_dt_match(dt_root, compat); 853 if (score > 0 && score < best_score) { 854 best_data = data; 855 best_score = score; 856 } 857 } 858 if (!best_data) { 859 const char *prop; 860 int size; 861 862 pr_err("\n unrecognized device tree list:\n[ "); 863 864 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 865 if (prop) { 866 while (size > 0) { 867 printk("'%s' ", prop); 868 size -= strlen(prop) + 1; 869 prop += strlen(prop) + 1; 870 } 871 } 872 printk("]\n\n"); 873 return NULL; 874 } 875 876 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name()); 877 878 return best_data; 879 } 880 881 #ifdef CONFIG_BLK_DEV_INITRD 882 #ifndef __early_init_dt_declare_initrd 883 static void __early_init_dt_declare_initrd(unsigned long start, 884 unsigned long end) 885 { 886 initrd_start = (unsigned long)__va(start); 887 initrd_end = (unsigned long)__va(end); 888 initrd_below_start_ok = 1; 889 } 890 #endif 891 892 /** 893 * early_init_dt_check_for_initrd - Decode initrd location from flat tree 894 * @node: reference to node containing initrd location ('chosen') 895 */ 896 static void __init early_init_dt_check_for_initrd(unsigned long node) 897 { 898 u64 start, end; 899 int len; 900 const __be32 *prop; 901 902 pr_debug("Looking for initrd properties... "); 903 904 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len); 905 if (!prop) 906 return; 907 start = of_read_number(prop, len/4); 908 909 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len); 910 if (!prop) 911 return; 912 end = of_read_number(prop, len/4); 913 914 __early_init_dt_declare_initrd(start, end); 915 916 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", 917 (unsigned long long)start, (unsigned long long)end); 918 } 919 #else 920 static inline void early_init_dt_check_for_initrd(unsigned long node) 921 { 922 } 923 #endif /* CONFIG_BLK_DEV_INITRD */ 924 925 #ifdef CONFIG_SERIAL_EARLYCON 926 927 int __init early_init_dt_scan_chosen_stdout(void) 928 { 929 int offset; 930 const char *p, *q, *options = NULL; 931 int l; 932 const struct earlycon_id *match; 933 const void *fdt = initial_boot_params; 934 935 offset = fdt_path_offset(fdt, "/chosen"); 936 if (offset < 0) 937 offset = fdt_path_offset(fdt, "/chosen@0"); 938 if (offset < 0) 939 return -ENOENT; 940 941 p = fdt_getprop(fdt, offset, "stdout-path", &l); 942 if (!p) 943 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l); 944 if (!p || !l) 945 return -ENOENT; 946 947 q = strchrnul(p, ':'); 948 if (*q != '\0') 949 options = q + 1; 950 l = q - p; 951 952 /* Get the node specified by stdout-path */ 953 offset = fdt_path_offset_namelen(fdt, p, l); 954 if (offset < 0) { 955 pr_warn("earlycon: stdout-path %.*s not found\n", l, p); 956 return 0; 957 } 958 959 for (match = __earlycon_table; match < __earlycon_table_end; match++) { 960 if (!match->compatible[0]) 961 continue; 962 963 if (fdt_node_check_compatible(fdt, offset, match->compatible)) 964 continue; 965 966 of_setup_earlycon(match, offset, options); 967 return 0; 968 } 969 return -ENODEV; 970 } 971 #endif 972 973 /** 974 * early_init_dt_scan_root - fetch the top level address and size cells 975 */ 976 int __init early_init_dt_scan_root(unsigned long node, const char *uname, 977 int depth, void *data) 978 { 979 const __be32 *prop; 980 981 if (depth != 0) 982 return 0; 983 984 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 985 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 986 987 prop = of_get_flat_dt_prop(node, "#size-cells", NULL); 988 if (prop) 989 dt_root_size_cells = be32_to_cpup(prop); 990 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells); 991 992 prop = of_get_flat_dt_prop(node, "#address-cells", NULL); 993 if (prop) 994 dt_root_addr_cells = be32_to_cpup(prop); 995 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells); 996 997 /* break now */ 998 return 1; 999 } 1000 1001 u64 __init dt_mem_next_cell(int s, const __be32 **cellp) 1002 { 1003 const __be32 *p = *cellp; 1004 1005 *cellp = p + s; 1006 return of_read_number(p, s); 1007 } 1008 1009 /** 1010 * early_init_dt_scan_memory - Look for an parse memory nodes 1011 */ 1012 int __init early_init_dt_scan_memory(unsigned long node, const char *uname, 1013 int depth, void *data) 1014 { 1015 const char *type = of_get_flat_dt_prop(node, "device_type", NULL); 1016 const __be32 *reg, *endp; 1017 int l; 1018 1019 /* We are scanning "memory" nodes only */ 1020 if (type == NULL) { 1021 /* 1022 * The longtrail doesn't have a device_type on the 1023 * /memory node, so look for the node called /memory@0. 1024 */ 1025 if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0) 1026 return 0; 1027 } else if (strcmp(type, "memory") != 0) 1028 return 0; 1029 1030 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l); 1031 if (reg == NULL) 1032 reg = of_get_flat_dt_prop(node, "reg", &l); 1033 if (reg == NULL) 1034 return 0; 1035 1036 endp = reg + (l / sizeof(__be32)); 1037 1038 pr_debug("memory scan node %s, reg size %d,\n", uname, l); 1039 1040 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) { 1041 u64 base, size; 1042 1043 base = dt_mem_next_cell(dt_root_addr_cells, ®); 1044 size = dt_mem_next_cell(dt_root_size_cells, ®); 1045 1046 if (size == 0) 1047 continue; 1048 pr_debug(" - %llx , %llx\n", (unsigned long long)base, 1049 (unsigned long long)size); 1050 1051 early_init_dt_add_memory_arch(base, size); 1052 } 1053 1054 return 0; 1055 } 1056 1057 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, 1058 int depth, void *data) 1059 { 1060 int l; 1061 const char *p; 1062 1063 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); 1064 1065 if (depth != 1 || !data || 1066 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0)) 1067 return 0; 1068 1069 early_init_dt_check_for_initrd(node); 1070 1071 /* Retrieve command line */ 1072 p = of_get_flat_dt_prop(node, "bootargs", &l); 1073 if (p != NULL && l > 0) 1074 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE)); 1075 1076 /* 1077 * CONFIG_CMDLINE is meant to be a default in case nothing else 1078 * managed to set the command line, unless CONFIG_CMDLINE_FORCE 1079 * is set in which case we override whatever was found earlier. 1080 */ 1081 #ifdef CONFIG_CMDLINE 1082 #if defined(CONFIG_CMDLINE_EXTEND) 1083 strlcat(data, " ", COMMAND_LINE_SIZE); 1084 strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1085 #elif defined(CONFIG_CMDLINE_FORCE) 1086 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1087 #else 1088 /* No arguments from boot loader, use kernel's cmdl*/ 1089 if (!((char *)data)[0]) 1090 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 1091 #endif 1092 #endif /* CONFIG_CMDLINE */ 1093 1094 pr_debug("Command line is: %s\n", (char*)data); 1095 1096 /* break now */ 1097 return 1; 1098 } 1099 1100 #ifdef CONFIG_HAVE_MEMBLOCK 1101 #ifndef MIN_MEMBLOCK_ADDR 1102 #define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET) 1103 #endif 1104 #ifndef MAX_MEMBLOCK_ADDR 1105 #define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0) 1106 #endif 1107 1108 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) 1109 { 1110 const u64 phys_offset = MIN_MEMBLOCK_ADDR; 1111 1112 if (!PAGE_ALIGNED(base)) { 1113 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { 1114 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", 1115 base, base + size); 1116 return; 1117 } 1118 size -= PAGE_SIZE - (base & ~PAGE_MASK); 1119 base = PAGE_ALIGN(base); 1120 } 1121 size &= PAGE_MASK; 1122 1123 if (base > MAX_MEMBLOCK_ADDR) { 1124 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n", 1125 base, base + size); 1126 return; 1127 } 1128 1129 if (base + size - 1 > MAX_MEMBLOCK_ADDR) { 1130 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n", 1131 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size); 1132 size = MAX_MEMBLOCK_ADDR - base + 1; 1133 } 1134 1135 if (base + size < phys_offset) { 1136 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n", 1137 base, base + size); 1138 return; 1139 } 1140 if (base < phys_offset) { 1141 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n", 1142 base, phys_offset); 1143 size -= phys_offset - base; 1144 base = phys_offset; 1145 } 1146 memblock_add(base, size); 1147 } 1148 1149 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base, 1150 phys_addr_t size, bool nomap) 1151 { 1152 if (nomap) 1153 return memblock_remove(base, size); 1154 return memblock_reserve(base, size); 1155 } 1156 1157 /* 1158 * called from unflatten_device_tree() to bootstrap devicetree itself 1159 * Architectures can override this definition if memblock isn't used 1160 */ 1161 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align) 1162 { 1163 return __va(memblock_alloc(size, align)); 1164 } 1165 #else 1166 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) 1167 { 1168 WARN_ON(1); 1169 } 1170 1171 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base, 1172 phys_addr_t size, bool nomap) 1173 { 1174 pr_err("Reserved memory not supported, ignoring range %pa - %pa%s\n", 1175 &base, &size, nomap ? " (nomap)" : ""); 1176 return -ENOSYS; 1177 } 1178 1179 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align) 1180 { 1181 WARN_ON(1); 1182 return NULL; 1183 } 1184 #endif 1185 1186 bool __init early_init_dt_verify(void *params) 1187 { 1188 if (!params) 1189 return false; 1190 1191 /* check device tree validity */ 1192 if (fdt_check_header(params)) 1193 return false; 1194 1195 /* Setup flat device-tree pointer */ 1196 initial_boot_params = params; 1197 of_fdt_crc32 = crc32_be(~0, initial_boot_params, 1198 fdt_totalsize(initial_boot_params)); 1199 return true; 1200 } 1201 1202 1203 void __init early_init_dt_scan_nodes(void) 1204 { 1205 /* Retrieve various information from the /chosen node */ 1206 of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); 1207 1208 /* Initialize {size,address}-cells info */ 1209 of_scan_flat_dt(early_init_dt_scan_root, NULL); 1210 1211 /* Setup memory, calling early_init_dt_add_memory_arch */ 1212 of_scan_flat_dt(early_init_dt_scan_memory, NULL); 1213 } 1214 1215 bool __init early_init_dt_scan(void *params) 1216 { 1217 bool status; 1218 1219 status = early_init_dt_verify(params); 1220 if (!status) 1221 return false; 1222 1223 early_init_dt_scan_nodes(); 1224 return true; 1225 } 1226 1227 /** 1228 * unflatten_device_tree - create tree of device_nodes from flat blob 1229 * 1230 * unflattens the device-tree passed by the firmware, creating the 1231 * tree of struct device_node. It also fills the "name" and "type" 1232 * pointers of the nodes so the normal device-tree walking functions 1233 * can be used. 1234 */ 1235 void __init unflatten_device_tree(void) 1236 { 1237 __unflatten_device_tree(initial_boot_params, NULL, &of_root, 1238 early_init_dt_alloc_memory_arch, false); 1239 1240 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ 1241 of_alias_scan(early_init_dt_alloc_memory_arch); 1242 } 1243 1244 /** 1245 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob 1246 * 1247 * Copies and unflattens the device-tree passed by the firmware, creating the 1248 * tree of struct device_node. It also fills the "name" and "type" 1249 * pointers of the nodes so the normal device-tree walking functions 1250 * can be used. This should only be used when the FDT memory has not been 1251 * reserved such is the case when the FDT is built-in to the kernel init 1252 * section. If the FDT memory is reserved already then unflatten_device_tree 1253 * should be used instead. 1254 */ 1255 void __init unflatten_and_copy_device_tree(void) 1256 { 1257 int size; 1258 void *dt; 1259 1260 if (!initial_boot_params) { 1261 pr_warn("No valid device tree found, continuing without\n"); 1262 return; 1263 } 1264 1265 size = fdt_totalsize(initial_boot_params); 1266 dt = early_init_dt_alloc_memory_arch(size, 1267 roundup_pow_of_two(FDT_V17_SIZE)); 1268 1269 if (dt) { 1270 memcpy(dt, initial_boot_params, size); 1271 initial_boot_params = dt; 1272 } 1273 unflatten_device_tree(); 1274 } 1275 1276 #ifdef CONFIG_SYSFS 1277 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj, 1278 struct bin_attribute *bin_attr, 1279 char *buf, loff_t off, size_t count) 1280 { 1281 memcpy(buf, initial_boot_params + off, count); 1282 return count; 1283 } 1284 1285 static int __init of_fdt_raw_init(void) 1286 { 1287 static struct bin_attribute of_fdt_raw_attr = 1288 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0); 1289 1290 if (!initial_boot_params) 1291 return 0; 1292 1293 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params, 1294 fdt_totalsize(initial_boot_params))) { 1295 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n"); 1296 return 0; 1297 } 1298 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params); 1299 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr); 1300 } 1301 late_initcall(of_fdt_raw_init); 1302 #endif 1303 1304 #endif /* CONFIG_OF_EARLY_FLATTREE */ 1305