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v5.9
   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/crc32.h>
  12#include <linux/kernel.h>
  13#include <linux/initrd.h>
 
  14#include <linux/memblock.h>
  15#include <linux/mutex.h>
  16#include <linux/of.h>
  17#include <linux/of_fdt.h>
  18#include <linux/of_reserved_mem.h>
  19#include <linux/sizes.h>
  20#include <linux/string.h>
  21#include <linux/errno.h>
  22#include <linux/slab.h>
  23#include <linux/libfdt.h>
  24#include <linux/debugfs.h>
  25#include <linux/serial_core.h>
  26#include <linux/sysfs.h>
  27#include <linux/random.h>
  28
  29#include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  30#include <asm/page.h>
  31
  32#include "of_private.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 */
  42void __init 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 __be32 *addr_prop;
  50	const __be32 *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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  82static bool of_fdt_device_is_available(const void *blob, unsigned long node)
  83{
  84	const char *status = fdt_getprop(blob, node, "status", NULL);
  85
  86	if (!status)
  87		return true;
  88
  89	if (!strcmp(status, "ok") || !strcmp(status, "okay"))
  90		return true;
  91
  92	return false;
  93}
  94
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  95static void *unflatten_dt_alloc(void **mem, unsigned long size,
  96				       unsigned long align)
  97{
  98	void *res;
  99
 100	*mem = PTR_ALIGN(*mem, align);
 101	res = *mem;
 102	*mem += size;
 103
 104	return res;
 105}
 106
 107static void populate_properties(const void *blob,
 108				int offset,
 109				void **mem,
 110				struct device_node *np,
 111				const char *nodename,
 112				bool dryrun)
 113{
 114	struct property *pp, **pprev = NULL;
 115	int cur;
 116	bool has_name = false;
 117
 118	pprev = &np->properties;
 119	for (cur = fdt_first_property_offset(blob, offset);
 120	     cur >= 0;
 121	     cur = fdt_next_property_offset(blob, cur)) {
 122		const __be32 *val;
 123		const char *pname;
 124		u32 sz;
 125
 126		val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
 127		if (!val) {
 128			pr_warn("Cannot locate property at 0x%x\n", cur);
 129			continue;
 130		}
 131
 132		if (!pname) {
 133			pr_warn("Cannot find property name at 0x%x\n", cur);
 134			continue;
 135		}
 136
 137		if (!strcmp(pname, "name"))
 138			has_name = true;
 139
 140		pp = unflatten_dt_alloc(mem, sizeof(struct property),
 141					__alignof__(struct property));
 142		if (dryrun)
 143			continue;
 144
 145		/* We accept flattened tree phandles either in
 146		 * ePAPR-style "phandle" properties, or the
 147		 * legacy "linux,phandle" properties.  If both
 148		 * appear and have different values, things
 149		 * will get weird. Don't do that.
 150		 */
 151		if (!strcmp(pname, "phandle") ||
 152		    !strcmp(pname, "linux,phandle")) {
 153			if (!np->phandle)
 154				np->phandle = be32_to_cpup(val);
 155		}
 156
 157		/* And we process the "ibm,phandle" property
 158		 * used in pSeries dynamic device tree
 159		 * stuff
 160		 */
 161		if (!strcmp(pname, "ibm,phandle"))
 162			np->phandle = be32_to_cpup(val);
 163
 164		pp->name   = (char *)pname;
 165		pp->length = sz;
 166		pp->value  = (__be32 *)val;
 167		*pprev     = pp;
 168		pprev      = &pp->next;
 169	}
 170
 171	/* With version 0x10 we may not have the name property,
 172	 * recreate it here from the unit name if absent
 173	 */
 174	if (!has_name) {
 175		const char *p = nodename, *ps = p, *pa = NULL;
 176		int len;
 177
 178		while (*p) {
 179			if ((*p) == '@')
 180				pa = p;
 181			else if ((*p) == '/')
 182				ps = p + 1;
 183			p++;
 184		}
 185
 186		if (pa < ps)
 187			pa = p;
 188		len = (pa - ps) + 1;
 189		pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
 190					__alignof__(struct property));
 191		if (!dryrun) {
 192			pp->name   = "name";
 193			pp->length = len;
 194			pp->value  = pp + 1;
 195			*pprev     = pp;
 196			pprev      = &pp->next;
 197			memcpy(pp->value, ps, len - 1);
 198			((char *)pp->value)[len - 1] = 0;
 199			pr_debug("fixed up name for %s -> %s\n",
 200				 nodename, (char *)pp->value);
 201		}
 202	}
 203
 204	if (!dryrun)
 205		*pprev = NULL;
 206}
 207
 208static bool populate_node(const void *blob,
 209			  int offset,
 210			  void **mem,
 211			  struct device_node *dad,
 212			  struct device_node **pnp,
 213			  bool dryrun)
 214{
 215	struct device_node *np;
 216	const char *pathp;
 217	unsigned int l, allocl;
 218
 219	pathp = fdt_get_name(blob, offset, &l);
 220	if (!pathp) {
 221		*pnp = NULL;
 222		return false;
 223	}
 224
 225	allocl = ++l;
 226
 227	np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
 228				__alignof__(struct device_node));
 229	if (!dryrun) {
 230		char *fn;
 231		of_node_init(np);
 232		np->full_name = fn = ((char *)np) + sizeof(*np);
 233
 234		memcpy(fn, pathp, l);
 235
 236		if (dad != NULL) {
 237			np->parent = dad;
 238			np->sibling = dad->child;
 239			dad->child = np;
 240		}
 241	}
 242
 243	populate_properties(blob, offset, mem, np, pathp, dryrun);
 244	if (!dryrun) {
 245		np->name = of_get_property(np, "name", NULL);
 
 
 246		if (!np->name)
 247			np->name = "<NULL>";
 
 
 248	}
 249
 250	*pnp = np;
 251	return true;
 252}
 253
 254static void reverse_nodes(struct device_node *parent)
 255{
 256	struct device_node *child, *next;
 257
 258	/* In-depth first */
 259	child = parent->child;
 260	while (child) {
 261		reverse_nodes(child);
 262
 263		child = child->sibling;
 264	}
 265
 266	/* Reverse the nodes in the child list */
 267	child = parent->child;
 268	parent->child = NULL;
 269	while (child) {
 270		next = child->sibling;
 271
 272		child->sibling = parent->child;
 273		parent->child = child;
 274		child = next;
 275	}
 276}
 277
 278/**
 279 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
 280 * @blob: The parent device tree blob
 281 * @mem: Memory chunk to use for allocating device nodes and properties
 282 * @dad: Parent struct device_node
 283 * @nodepp: The device_node tree created by the call
 284 *
 285 * It returns the size of unflattened device tree or error code
 286 */
 287static int unflatten_dt_nodes(const void *blob,
 288			      void *mem,
 289			      struct device_node *dad,
 290			      struct device_node **nodepp)
 291{
 292	struct device_node *root;
 293	int offset = 0, depth = 0, initial_depth = 0;
 294#define FDT_MAX_DEPTH	64
 295	struct device_node *nps[FDT_MAX_DEPTH];
 296	void *base = mem;
 297	bool dryrun = !base;
 298
 299	if (nodepp)
 300		*nodepp = NULL;
 301
 302	/*
 303	 * We're unflattening device sub-tree if @dad is valid. There are
 304	 * possibly multiple nodes in the first level of depth. We need
 305	 * set @depth to 1 to make fdt_next_node() happy as it bails
 306	 * immediately when negative @depth is found. Otherwise, the device
 307	 * nodes except the first one won't be unflattened successfully.
 308	 */
 309	if (dad)
 310		depth = initial_depth = 1;
 311
 312	root = dad;
 313	nps[depth] = dad;
 314
 315	for (offset = 0;
 316	     offset >= 0 && depth >= initial_depth;
 317	     offset = fdt_next_node(blob, offset, &depth)) {
 318		if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
 319			continue;
 320
 321		if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
 322		    !of_fdt_device_is_available(blob, offset))
 323			continue;
 324
 325		if (!populate_node(blob, offset, &mem, nps[depth],
 326				   &nps[depth+1], dryrun))
 327			return mem - base;
 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 *
 353 * unflattens a device-tree, creating the
 354 * tree of struct device_node. It also fills the "name" and "type"
 355 * pointers of the nodes so the normal device-tree walking functions
 356 * can be used.
 357 * @blob: The blob to expand
 358 * @dad: Parent device node
 359 * @mynodes: The device_node tree created by the call
 360 * @dt_alloc: An allocator that provides a virtual address to memory
 361 * for the resulting tree
 362 * @detached: if true set OF_DETACHED on @mynodes
 363 *
 364 * Returns NULL on failure or the memory chunk containing the unflattened
 365 * device tree on success.
 366 */
 367void *__unflatten_device_tree(const void *blob,
 368			      struct device_node *dad,
 369			      struct device_node **mynodes,
 370			      void *(*dt_alloc)(u64 size, u64 align),
 371			      bool detached)
 372{
 373	int size;
 374	void *mem;
 375
 376	pr_debug(" -> unflatten_device_tree()\n");
 377
 378	if (!blob) {
 379		pr_debug("No device tree pointer\n");
 380		return NULL;
 381	}
 382
 383	pr_debug("Unflattening device tree:\n");
 384	pr_debug("magic: %08x\n", fdt_magic(blob));
 385	pr_debug("size: %08x\n", fdt_totalsize(blob));
 386	pr_debug("version: %08x\n", fdt_version(blob));
 387
 388	if (fdt_check_header(blob)) {
 389		pr_err("Invalid device tree blob header\n");
 390		return NULL;
 391	}
 392
 393	/* First pass, scan for size */
 394	size = unflatten_dt_nodes(blob, NULL, dad, NULL);
 395	if (size < 0)
 396		return NULL;
 397
 398	size = ALIGN(size, 4);
 399	pr_debug("  size is %d, allocating...\n", size);
 400
 401	/* Allocate memory for the expanded device tree */
 402	mem = dt_alloc(size + 4, __alignof__(struct device_node));
 403	if (!mem)
 404		return NULL;
 405
 406	memset(mem, 0, size);
 407
 408	*(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 409
 410	pr_debug("  unflattening %p...\n", mem);
 411
 412	/* Second pass, do actual unflattening */
 413	unflatten_dt_nodes(blob, mem, dad, mynodes);
 414	if (be32_to_cpup(mem + size) != 0xdeadbeef)
 415		pr_warn("End of tree marker overwritten: %08x\n",
 416			be32_to_cpup(mem + size));
 417
 418	if (detached && mynodes) {
 419		of_node_set_flag(*mynodes, OF_DETACHED);
 420		pr_debug("unflattened tree is detached\n");
 421	}
 422
 423	pr_debug(" <- unflatten_device_tree()\n");
 424	return mem;
 425}
 426
 427static void *kernel_tree_alloc(u64 size, u64 align)
 428{
 429	return kzalloc(size, GFP_KERNEL);
 430}
 431
 432static DEFINE_MUTEX(of_fdt_unflatten_mutex);
 433
 434/**
 435 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 436 * @blob: Flat device tree blob
 437 * @dad: Parent device node
 438 * @mynodes: The device tree created by the call
 439 *
 440 * unflattens the device-tree passed by the firmware, creating the
 441 * tree of struct device_node. It also fills the "name" and "type"
 442 * pointers of the nodes so the normal device-tree walking functions
 443 * can be used.
 444 *
 445 * Returns NULL on failure or the memory chunk containing the unflattened
 446 * device tree on success.
 447 */
 448void *of_fdt_unflatten_tree(const unsigned long *blob,
 449			    struct device_node *dad,
 450			    struct device_node **mynodes)
 451{
 452	void *mem;
 453
 454	mutex_lock(&of_fdt_unflatten_mutex);
 455	mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
 456				      true);
 457	mutex_unlock(&of_fdt_unflatten_mutex);
 458
 459	return mem;
 460}
 461EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 462
 463/* Everything below here references initial_boot_params directly. */
 464int __initdata dt_root_addr_cells;
 465int __initdata dt_root_size_cells;
 466
 467void *initial_boot_params __ro_after_init;
 468
 469#ifdef CONFIG_OF_EARLY_FLATTREE
 470
 471static u32 of_fdt_crc32;
 472
 473/**
 474 * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
 475 */
 476static int __init __reserved_mem_reserve_reg(unsigned long node,
 477					     const char *uname)
 478{
 479	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 480	phys_addr_t base, size;
 481	int len;
 482	const __be32 *prop;
 483	int first = 1;
 484	bool nomap;
 485
 486	prop = of_get_flat_dt_prop(node, "reg", &len);
 487	if (!prop)
 488		return -ENOENT;
 489
 490	if (len && len % t_len != 0) {
 491		pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 492		       uname);
 493		return -EINVAL;
 494	}
 495
 496	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 497
 498	while (len >= t_len) {
 499		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 500		size = dt_mem_next_cell(dt_root_size_cells, &prop);
 501
 502		if (size &&
 503		    early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 504			pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 505				uname, &base, (unsigned long)size / SZ_1M);
 506		else
 507			pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 508				uname, &base, (unsigned long)size / SZ_1M);
 509
 510		len -= t_len;
 511		if (first) {
 512			fdt_reserved_mem_save_node(node, uname, base, size);
 513			first = 0;
 514		}
 515	}
 516	return 0;
 517}
 518
 519/**
 520 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 521 * in /reserved-memory matches the values supported by the current implementation,
 522 * also check if ranges property has been provided
 523 */
 524static int __init __reserved_mem_check_root(unsigned long node)
 525{
 526	const __be32 *prop;
 527
 528	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 529	if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 530		return -EINVAL;
 531
 532	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 533	if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 534		return -EINVAL;
 535
 536	prop = of_get_flat_dt_prop(node, "ranges", NULL);
 537	if (!prop)
 538		return -EINVAL;
 539	return 0;
 540}
 541
 542/**
 543 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 544 */
 545static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 546					  int depth, void *data)
 547{
 548	static int found;
 549	int err;
 550
 551	if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 552		if (__reserved_mem_check_root(node) != 0) {
 553			pr_err("Reserved memory: unsupported node format, ignoring\n");
 554			/* break scan */
 555			return 1;
 556		}
 557		found = 1;
 558		/* scan next node */
 559		return 0;
 560	} else if (!found) {
 561		/* scan next node */
 562		return 0;
 563	} else if (found && depth < 2) {
 564		/* scanning of /reserved-memory has been finished */
 565		return 1;
 566	}
 567
 568	if (!of_fdt_device_is_available(initial_boot_params, node))
 569		return 0;
 570
 571	err = __reserved_mem_reserve_reg(node, uname);
 572	if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 573		fdt_reserved_mem_save_node(node, uname, 0, 0);
 574
 575	/* scan next node */
 576	return 0;
 577}
 578
 579/**
 580 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 581 *
 582 * This function grabs memory from early allocator for device exclusive use
 583 * defined in device tree structures. It should be called by arch specific code
 584 * once the early allocator (i.e. memblock) has been fully activated.
 585 */
 586void __init early_init_fdt_scan_reserved_mem(void)
 587{
 588	int n;
 589	u64 base, size;
 590
 591	if (!initial_boot_params)
 592		return;
 593
 594	/* Process header /memreserve/ fields */
 595	for (n = 0; ; n++) {
 596		fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 597		if (!size)
 598			break;
 599		early_init_dt_reserve_memory_arch(base, size, false);
 600	}
 601
 602	of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 603	fdt_init_reserved_mem();
 604}
 605
 606/**
 607 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
 608 */
 609void __init early_init_fdt_reserve_self(void)
 610{
 611	if (!initial_boot_params)
 612		return;
 613
 614	/* Reserve the dtb region */
 615	early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
 616					  fdt_totalsize(initial_boot_params),
 617					  false);
 618}
 619
 620/**
 621 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 622 * @it: callback function
 623 * @data: context data pointer
 624 *
 625 * This function is used to scan the flattened device-tree, it is
 626 * used to extract the memory information at boot before we can
 627 * unflatten the tree
 628 */
 629int __init of_scan_flat_dt(int (*it)(unsigned long node,
 630				     const char *uname, int depth,
 631				     void *data),
 632			   void *data)
 633{
 634	const void *blob = initial_boot_params;
 635	const char *pathp;
 636	int offset, rc = 0, depth = -1;
 637
 638	if (!blob)
 639		return 0;
 640
 641	for (offset = fdt_next_node(blob, -1, &depth);
 642	     offset >= 0 && depth >= 0 && !rc;
 643	     offset = fdt_next_node(blob, offset, &depth)) {
 644
 645		pathp = fdt_get_name(blob, offset, NULL);
 
 
 646		rc = it(offset, pathp, depth, data);
 647	}
 648	return rc;
 649}
 650
 651/**
 652 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
 653 * @it: callback function
 654 * @data: context data pointer
 655 *
 656 * This function is used to scan sub-nodes of a node.
 657 */
 658int __init of_scan_flat_dt_subnodes(unsigned long parent,
 659				    int (*it)(unsigned long node,
 660					      const char *uname,
 661					      void *data),
 662				    void *data)
 663{
 664	const void *blob = initial_boot_params;
 665	int node;
 666
 667	fdt_for_each_subnode(node, blob, parent) {
 668		const char *pathp;
 669		int rc;
 670
 671		pathp = fdt_get_name(blob, node, NULL);
 
 
 672		rc = it(node, pathp, data);
 673		if (rc)
 674			return rc;
 675	}
 676	return 0;
 677}
 678
 679/**
 680 * of_get_flat_dt_subnode_by_name - get the subnode by given name
 681 *
 682 * @node: the parent node
 683 * @uname: the name of subnode
 684 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
 685 */
 686
 687int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
 688{
 689	return fdt_subnode_offset(initial_boot_params, node, uname);
 690}
 691
 692/**
 693 * of_get_flat_dt_root - find the root node in the flat blob
 694 */
 695unsigned long __init of_get_flat_dt_root(void)
 696{
 697	return 0;
 698}
 699
 700/**
 
 
 
 
 
 
 
 
 701 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 702 *
 703 * This function can be used within scan_flattened_dt callback to get
 704 * access to properties
 705 */
 706const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 707				       int *size)
 708{
 709	return fdt_getprop(initial_boot_params, node, name, size);
 710}
 711
 712/**
 713 * of_fdt_is_compatible - Return true if given node from the given blob has
 714 * compat in its compatible list
 715 * @blob: A device tree blob
 716 * @node: node to test
 717 * @compat: compatible string to compare with compatible list.
 718 *
 719 * On match, returns a non-zero value with smaller values returned for more
 720 * specific compatible values.
 721 */
 722static int of_fdt_is_compatible(const void *blob,
 723		      unsigned long node, const char *compat)
 724{
 725	const char *cp;
 726	int cplen;
 727	unsigned long l, score = 0;
 728
 729	cp = fdt_getprop(blob, node, "compatible", &cplen);
 730	if (cp == NULL)
 731		return 0;
 732	while (cplen > 0) {
 733		score++;
 734		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 735			return score;
 736		l = strlen(cp) + 1;
 737		cp += l;
 738		cplen -= l;
 739	}
 740
 741	return 0;
 742}
 743
 744/**
 745 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 746 * @node: node to test
 747 * @compat: compatible string to compare with compatible list.
 748 */
 749int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 750{
 751	return of_fdt_is_compatible(initial_boot_params, node, compat);
 752}
 753
 754/**
 755 * of_flat_dt_match - Return true if node matches a list of compatible values
 756 */
 757static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 758{
 759	unsigned int tmp, score = 0;
 760
 761	if (!compat)
 762		return 0;
 763
 764	while (*compat) {
 765		tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
 766		if (tmp && (score == 0 || (tmp < score)))
 767			score = tmp;
 768		compat++;
 769	}
 770
 771	return score;
 772}
 773
 774/**
 775 * of_get_flat_dt_prop - Given a node in the flat blob, return the phandle
 776 */
 777uint32_t __init of_get_flat_dt_phandle(unsigned long node)
 778{
 779	return fdt_get_phandle(initial_boot_params, node);
 780}
 781
 782struct fdt_scan_status {
 783	const char *name;
 784	int namelen;
 785	int depth;
 786	int found;
 787	int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 788	void *data;
 789};
 790
 791const char * __init of_flat_dt_get_machine_name(void)
 792{
 793	const char *name;
 794	unsigned long dt_root = of_get_flat_dt_root();
 795
 796	name = of_get_flat_dt_prop(dt_root, "model", NULL);
 797	if (!name)
 798		name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 799	return name;
 800}
 801
 802/**
 803 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 804 *
 805 * @default_match: A machine specific ptr to return in case of no match.
 806 * @get_next_compat: callback function to return next compatible match table.
 807 *
 808 * Iterate through machine match tables to find the best match for the machine
 809 * compatible string in the FDT.
 810 */
 811const void * __init of_flat_dt_match_machine(const void *default_match,
 812		const void * (*get_next_compat)(const char * const**))
 813{
 814	const void *data = NULL;
 815	const void *best_data = default_match;
 816	const char *const *compat;
 817	unsigned long dt_root;
 818	unsigned int best_score = ~1, score = 0;
 819
 820	dt_root = of_get_flat_dt_root();
 821	while ((data = get_next_compat(&compat))) {
 822		score = of_flat_dt_match(dt_root, compat);
 823		if (score > 0 && score < best_score) {
 824			best_data = data;
 825			best_score = score;
 826		}
 827	}
 828	if (!best_data) {
 829		const char *prop;
 830		int size;
 831
 832		pr_err("\n unrecognized device tree list:\n[ ");
 833
 834		prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 835		if (prop) {
 836			while (size > 0) {
 837				printk("'%s' ", prop);
 838				size -= strlen(prop) + 1;
 839				prop += strlen(prop) + 1;
 840			}
 841		}
 842		printk("]\n\n");
 843		return NULL;
 844	}
 845
 846	pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 847
 848	return best_data;
 849}
 850
 851#ifdef CONFIG_BLK_DEV_INITRD
 
 852static void __early_init_dt_declare_initrd(unsigned long start,
 853					   unsigned long end)
 854{
 855	/* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is
 856	 * enabled since __va() is called too early. ARM64 does make use
 857	 * of phys_initrd_start/phys_initrd_size so we can skip this
 858	 * conversion.
 859	 */
 860	if (!IS_ENABLED(CONFIG_ARM64)) {
 861		initrd_start = (unsigned long)__va(start);
 862		initrd_end = (unsigned long)__va(end);
 863		initrd_below_start_ok = 1;
 864	}
 865}
 
 866
 867/**
 868 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 869 * @node: reference to node containing initrd location ('chosen')
 870 */
 871static void __init early_init_dt_check_for_initrd(unsigned long node)
 872{
 873	u64 start, end;
 874	int len;
 875	const __be32 *prop;
 876
 877	pr_debug("Looking for initrd properties... ");
 878
 879	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 880	if (!prop)
 881		return;
 882	start = of_read_number(prop, len/4);
 883
 884	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 885	if (!prop)
 886		return;
 887	end = of_read_number(prop, len/4);
 888
 889	__early_init_dt_declare_initrd(start, end);
 890	phys_initrd_start = start;
 891	phys_initrd_size = end - start;
 892
 893	pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 894		 (unsigned long long)start, (unsigned long long)end);
 895}
 896#else
 897static inline void early_init_dt_check_for_initrd(unsigned long node)
 898{
 899}
 900#endif /* CONFIG_BLK_DEV_INITRD */
 901
 902#ifdef CONFIG_SERIAL_EARLYCON
 903
 904int __init early_init_dt_scan_chosen_stdout(void)
 905{
 906	int offset;
 907	const char *p, *q, *options = NULL;
 908	int l;
 909	const struct earlycon_id **p_match;
 910	const void *fdt = initial_boot_params;
 911
 912	offset = fdt_path_offset(fdt, "/chosen");
 913	if (offset < 0)
 914		offset = fdt_path_offset(fdt, "/chosen@0");
 915	if (offset < 0)
 916		return -ENOENT;
 917
 918	p = fdt_getprop(fdt, offset, "stdout-path", &l);
 919	if (!p)
 920		p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 921	if (!p || !l)
 922		return -ENOENT;
 923
 924	q = strchrnul(p, ':');
 925	if (*q != '\0')
 926		options = q + 1;
 927	l = q - p;
 928
 929	/* Get the node specified by stdout-path */
 930	offset = fdt_path_offset_namelen(fdt, p, l);
 931	if (offset < 0) {
 932		pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
 933		return 0;
 934	}
 935
 936	for (p_match = __earlycon_table; p_match < __earlycon_table_end;
 937	     p_match++) {
 938		const struct earlycon_id *match = *p_match;
 939
 940		if (!match->compatible[0])
 941			continue;
 942
 943		if (fdt_node_check_compatible(fdt, offset, match->compatible))
 944			continue;
 945
 946		if (of_setup_earlycon(match, offset, options) == 0)
 947			return 0;
 948	}
 949	return -ENODEV;
 950}
 951#endif
 952
 953/**
 954 * early_init_dt_scan_root - fetch the top level address and size cells
 955 */
 956int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 957				   int depth, void *data)
 958{
 959	const __be32 *prop;
 960
 961	if (depth != 0)
 962		return 0;
 963
 964	dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 965	dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 966
 967	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 968	if (prop)
 969		dt_root_size_cells = be32_to_cpup(prop);
 970	pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 971
 972	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 973	if (prop)
 974		dt_root_addr_cells = be32_to_cpup(prop);
 975	pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 976
 977	/* break now */
 978	return 1;
 979}
 980
 981u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
 982{
 983	const __be32 *p = *cellp;
 984
 985	*cellp = p + s;
 986	return of_read_number(p, s);
 987}
 988
 989/**
 990 * early_init_dt_scan_memory - Look for and parse memory nodes
 991 */
 992int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 993				     int depth, void *data)
 994{
 995	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 996	const __be32 *reg, *endp;
 997	int l;
 998	bool hotpluggable;
 999
1000	/* We are scanning "memory" nodes only */
1001	if (type == NULL || strcmp(type, "memory") != 0)
 
 
 
 
 
 
 
1002		return 0;
1003
1004	reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1005	if (reg == NULL)
1006		reg = of_get_flat_dt_prop(node, "reg", &l);
1007	if (reg == NULL)
1008		return 0;
1009
1010	endp = reg + (l / sizeof(__be32));
1011	hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1012
1013	pr_debug("memory scan node %s, reg size %d,\n", uname, l);
1014
1015	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1016		u64 base, size;
1017
1018		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
1019		size = dt_mem_next_cell(dt_root_size_cells, &reg);
1020
1021		if (size == 0)
1022			continue;
1023		pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
1024		    (unsigned long long)size);
1025
1026		early_init_dt_add_memory_arch(base, size);
1027
1028		if (!hotpluggable)
1029			continue;
1030
1031		if (early_init_dt_mark_hotplug_memory_arch(base, size))
1032			pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1033				base, base + size);
1034	}
1035
1036	return 0;
1037}
1038
1039int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
1040				     int depth, void *data)
1041{
1042	int l;
1043	const char *p;
1044	const void *rng_seed;
1045
1046	pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
1047
1048	if (depth != 1 || !data ||
1049	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
1050		return 0;
1051
1052	early_init_dt_check_for_initrd(node);
1053
1054	/* Retrieve command line */
1055	p = of_get_flat_dt_prop(node, "bootargs", &l);
1056	if (p != NULL && l > 0)
1057		strlcpy(data, p, min(l, COMMAND_LINE_SIZE));
1058
1059	/*
1060	 * CONFIG_CMDLINE is meant to be a default in case nothing else
1061	 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1062	 * is set in which case we override whatever was found earlier.
1063	 */
1064#ifdef CONFIG_CMDLINE
1065#if defined(CONFIG_CMDLINE_EXTEND)
1066	strlcat(data, " ", COMMAND_LINE_SIZE);
1067	strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1068#elif defined(CONFIG_CMDLINE_FORCE)
1069	strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1070#else
1071	/* No arguments from boot loader, use kernel's  cmdl*/
1072	if (!((char *)data)[0])
1073		strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1074#endif
1075#endif /* CONFIG_CMDLINE */
1076
1077	pr_debug("Command line is: %s\n", (char *)data);
1078
1079	rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1080	if (rng_seed && l > 0) {
1081		add_bootloader_randomness(rng_seed, l);
1082
1083		/* try to clear seed so it won't be found. */
1084		fdt_nop_property(initial_boot_params, node, "rng-seed");
1085
1086		/* update CRC check value */
1087		of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1088				fdt_totalsize(initial_boot_params));
1089	}
1090
1091	/* break now */
1092	return 1;
1093}
1094
 
1095#ifndef MIN_MEMBLOCK_ADDR
1096#define MIN_MEMBLOCK_ADDR	__pa(PAGE_OFFSET)
1097#endif
1098#ifndef MAX_MEMBLOCK_ADDR
1099#define MAX_MEMBLOCK_ADDR	((phys_addr_t)~0)
1100#endif
1101
1102void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1103{
1104	const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1105
1106	if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1107		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1108			base, base + size);
1109		return;
1110	}
1111
1112	if (!PAGE_ALIGNED(base)) {
 
 
 
 
 
1113		size -= PAGE_SIZE - (base & ~PAGE_MASK);
1114		base = PAGE_ALIGN(base);
1115	}
1116	size &= PAGE_MASK;
1117
1118	if (base > MAX_MEMBLOCK_ADDR) {
1119		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1120			base, base + size);
1121		return;
1122	}
1123
1124	if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1125		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1126			((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1127		size = MAX_MEMBLOCK_ADDR - base + 1;
1128	}
1129
1130	if (base + size < phys_offset) {
1131		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1132			base, base + size);
1133		return;
1134	}
1135	if (base < phys_offset) {
1136		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1137			base, phys_offset);
1138		size -= phys_offset - base;
1139		base = phys_offset;
1140	}
1141	memblock_add(base, size);
1142}
1143
1144int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1145{
1146	return memblock_mark_hotplug(base, size);
1147}
1148
1149int __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
1157static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
 
 
 
 
 
 
1158{
1159	void *ptr = memblock_alloc(size, align);
 
1160
1161	if (!ptr)
1162		panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1163		      __func__, size, align);
 
 
 
 
 
1164
1165	return ptr;
 
 
1166}
1167
1168bool __init early_init_dt_verify(void *params)
1169{
1170	if (!params)
1171		return false;
1172
1173	/* check device tree validity */
1174	if (fdt_check_header(params))
1175		return false;
1176
1177	/* Setup flat device-tree pointer */
1178	initial_boot_params = params;
1179	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1180				fdt_totalsize(initial_boot_params));
1181	return true;
1182}
1183
1184
1185void __init early_init_dt_scan_nodes(void)
1186{
1187	int rc = 0;
1188
1189	/* Retrieve various information from the /chosen node */
1190	rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1191	if (!rc)
1192		pr_warn("No chosen node found, continuing without\n");
1193
1194	/* Initialize {size,address}-cells info */
1195	of_scan_flat_dt(early_init_dt_scan_root, NULL);
1196
1197	/* Setup memory, calling early_init_dt_add_memory_arch */
1198	of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1199}
1200
1201bool __init early_init_dt_scan(void *params)
1202{
1203	bool status;
1204
1205	status = early_init_dt_verify(params);
1206	if (!status)
1207		return false;
1208
1209	early_init_dt_scan_nodes();
1210	return true;
1211}
1212
1213/**
1214 * unflatten_device_tree - create tree of device_nodes from flat blob
1215 *
1216 * unflattens the device-tree passed by the firmware, creating the
1217 * tree of struct device_node. It also fills the "name" and "type"
1218 * pointers of the nodes so the normal device-tree walking functions
1219 * can be used.
1220 */
1221void __init unflatten_device_tree(void)
1222{
1223	__unflatten_device_tree(initial_boot_params, NULL, &of_root,
1224				early_init_dt_alloc_memory_arch, false);
1225
1226	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1227	of_alias_scan(early_init_dt_alloc_memory_arch);
1228
1229	unittest_unflatten_overlay_base();
1230}
1231
1232/**
1233 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1234 *
1235 * Copies and unflattens the device-tree passed by the firmware, creating the
1236 * tree of struct device_node. It also fills the "name" and "type"
1237 * pointers of the nodes so the normal device-tree walking functions
1238 * can be used. This should only be used when the FDT memory has not been
1239 * reserved such is the case when the FDT is built-in to the kernel init
1240 * section. If the FDT memory is reserved already then unflatten_device_tree
1241 * should be used instead.
1242 */
1243void __init unflatten_and_copy_device_tree(void)
1244{
1245	int size;
1246	void *dt;
1247
1248	if (!initial_boot_params) {
1249		pr_warn("No valid device tree found, continuing without\n");
1250		return;
1251	}
1252
1253	size = fdt_totalsize(initial_boot_params);
1254	dt = early_init_dt_alloc_memory_arch(size,
1255					     roundup_pow_of_two(FDT_V17_SIZE));
1256
1257	if (dt) {
1258		memcpy(dt, initial_boot_params, size);
1259		initial_boot_params = dt;
1260	}
1261	unflatten_device_tree();
1262}
1263
1264#ifdef CONFIG_SYSFS
1265static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1266			       struct bin_attribute *bin_attr,
1267			       char *buf, loff_t off, size_t count)
1268{
1269	memcpy(buf, initial_boot_params + off, count);
1270	return count;
1271}
1272
1273static int __init of_fdt_raw_init(void)
1274{
1275	static struct bin_attribute of_fdt_raw_attr =
1276		__BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1277
1278	if (!initial_boot_params)
1279		return 0;
1280
1281	if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1282				     fdt_totalsize(initial_boot_params))) {
1283		pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1284		return 0;
1285	}
1286	of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1287	return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1288}
1289late_initcall(of_fdt_raw_init);
1290#endif
1291
1292#endif /* CONFIG_OF_EARLY_FLATTREE */
v4.17
   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/crc32.h>
  12#include <linux/kernel.h>
  13#include <linux/initrd.h>
  14#include <linux/bootmem.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
  29#include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  30#include <asm/page.h>
  31
  32#include "of_private.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 */
  42void 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 __be32 *addr_prop;
  50	const __be32 *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 */
  92static 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 */
 123bool 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
 133static bool of_fdt_device_is_available(const void *blob, unsigned long node)
 134{
 135	const char *status = fdt_getprop(blob, node, "status", NULL);
 136
 137	if (!status)
 138		return true;
 139
 140	if (!strcmp(status, "ok") || !strcmp(status, "okay"))
 141		return true;
 142
 143	return false;
 144}
 145
 146/**
 147 * of_fdt_match - Return true if node matches a list of compatible values
 148 */
 149int of_fdt_match(const void *blob, unsigned long node,
 150                 const char *const *compat)
 151{
 152	unsigned int tmp, score = 0;
 153
 154	if (!compat)
 155		return 0;
 156
 157	while (*compat) {
 158		tmp = of_fdt_is_compatible(blob, node, *compat);
 159		if (tmp && (score == 0 || (tmp < score)))
 160			score = tmp;
 161		compat++;
 162	}
 163
 164	return score;
 165}
 166
 167static void *unflatten_dt_alloc(void **mem, unsigned long size,
 168				       unsigned long align)
 169{
 170	void *res;
 171
 172	*mem = PTR_ALIGN(*mem, align);
 173	res = *mem;
 174	*mem += size;
 175
 176	return res;
 177}
 178
 179static void populate_properties(const void *blob,
 180				int offset,
 181				void **mem,
 182				struct device_node *np,
 183				const char *nodename,
 184				bool dryrun)
 185{
 186	struct property *pp, **pprev = NULL;
 187	int cur;
 188	bool has_name = false;
 189
 190	pprev = &np->properties;
 191	for (cur = fdt_first_property_offset(blob, offset);
 192	     cur >= 0;
 193	     cur = fdt_next_property_offset(blob, cur)) {
 194		const __be32 *val;
 195		const char *pname;
 196		u32 sz;
 197
 198		val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
 199		if (!val) {
 200			pr_warn("Cannot locate property at 0x%x\n", cur);
 201			continue;
 202		}
 203
 204		if (!pname) {
 205			pr_warn("Cannot find property name at 0x%x\n", cur);
 206			continue;
 207		}
 208
 209		if (!strcmp(pname, "name"))
 210			has_name = true;
 211
 212		pp = unflatten_dt_alloc(mem, sizeof(struct property),
 213					__alignof__(struct property));
 214		if (dryrun)
 215			continue;
 216
 217		/* We accept flattened tree phandles either in
 218		 * ePAPR-style "phandle" properties, or the
 219		 * legacy "linux,phandle" properties.  If both
 220		 * appear and have different values, things
 221		 * will get weird. Don't do that.
 222		 */
 223		if (!strcmp(pname, "phandle") ||
 224		    !strcmp(pname, "linux,phandle")) {
 225			if (!np->phandle)
 226				np->phandle = be32_to_cpup(val);
 227		}
 228
 229		/* And we process the "ibm,phandle" property
 230		 * used in pSeries dynamic device tree
 231		 * stuff
 232		 */
 233		if (!strcmp(pname, "ibm,phandle"))
 234			np->phandle = be32_to_cpup(val);
 235
 236		pp->name   = (char *)pname;
 237		pp->length = sz;
 238		pp->value  = (__be32 *)val;
 239		*pprev     = pp;
 240		pprev      = &pp->next;
 241	}
 242
 243	/* With version 0x10 we may not have the name property,
 244	 * recreate it here from the unit name if absent
 245	 */
 246	if (!has_name) {
 247		const char *p = nodename, *ps = p, *pa = NULL;
 248		int len;
 249
 250		while (*p) {
 251			if ((*p) == '@')
 252				pa = p;
 253			else if ((*p) == '/')
 254				ps = p + 1;
 255			p++;
 256		}
 257
 258		if (pa < ps)
 259			pa = p;
 260		len = (pa - ps) + 1;
 261		pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
 262					__alignof__(struct property));
 263		if (!dryrun) {
 264			pp->name   = "name";
 265			pp->length = len;
 266			pp->value  = pp + 1;
 267			*pprev     = pp;
 268			pprev      = &pp->next;
 269			memcpy(pp->value, ps, len - 1);
 270			((char *)pp->value)[len - 1] = 0;
 271			pr_debug("fixed up name for %s -> %s\n",
 272				 nodename, (char *)pp->value);
 273		}
 274	}
 275
 276	if (!dryrun)
 277		*pprev = NULL;
 278}
 279
 280static bool populate_node(const void *blob,
 281			  int offset,
 282			  void **mem,
 283			  struct device_node *dad,
 284			  struct device_node **pnp,
 285			  bool dryrun)
 286{
 287	struct device_node *np;
 288	const char *pathp;
 289	unsigned int l, allocl;
 290
 291	pathp = fdt_get_name(blob, offset, &l);
 292	if (!pathp) {
 293		*pnp = NULL;
 294		return false;
 295	}
 296
 297	allocl = ++l;
 298
 299	np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
 300				__alignof__(struct device_node));
 301	if (!dryrun) {
 302		char *fn;
 303		of_node_init(np);
 304		np->full_name = fn = ((char *)np) + sizeof(*np);
 305
 306		memcpy(fn, pathp, l);
 307
 308		if (dad != NULL) {
 309			np->parent = dad;
 310			np->sibling = dad->child;
 311			dad->child = np;
 312		}
 313	}
 314
 315	populate_properties(blob, offset, mem, np, pathp, dryrun);
 316	if (!dryrun) {
 317		np->name = of_get_property(np, "name", NULL);
 318		np->type = of_get_property(np, "device_type", NULL);
 319
 320		if (!np->name)
 321			np->name = "<NULL>";
 322		if (!np->type)
 323			np->type = "<NULL>";
 324	}
 325
 326	*pnp = np;
 327	return true;
 328}
 329
 330static void reverse_nodes(struct device_node *parent)
 331{
 332	struct device_node *child, *next;
 333
 334	/* In-depth first */
 335	child = parent->child;
 336	while (child) {
 337		reverse_nodes(child);
 338
 339		child = child->sibling;
 340	}
 341
 342	/* Reverse the nodes in the child list */
 343	child = parent->child;
 344	parent->child = NULL;
 345	while (child) {
 346		next = child->sibling;
 347
 348		child->sibling = parent->child;
 349		parent->child = child;
 350		child = next;
 351	}
 352}
 353
 354/**
 355 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
 356 * @blob: The parent device tree blob
 357 * @mem: Memory chunk to use for allocating device nodes and properties
 358 * @dad: Parent struct device_node
 359 * @nodepp: The device_node tree created by the call
 360 *
 361 * It returns the size of unflattened device tree or error code
 362 */
 363static int unflatten_dt_nodes(const void *blob,
 364			      void *mem,
 365			      struct device_node *dad,
 366			      struct device_node **nodepp)
 367{
 368	struct device_node *root;
 369	int offset = 0, depth = 0, initial_depth = 0;
 370#define FDT_MAX_DEPTH	64
 371	struct device_node *nps[FDT_MAX_DEPTH];
 372	void *base = mem;
 373	bool dryrun = !base;
 374
 375	if (nodepp)
 376		*nodepp = NULL;
 377
 378	/*
 379	 * We're unflattening device sub-tree if @dad is valid. There are
 380	 * possibly multiple nodes in the first level of depth. We need
 381	 * set @depth to 1 to make fdt_next_node() happy as it bails
 382	 * immediately when negative @depth is found. Otherwise, the device
 383	 * nodes except the first one won't be unflattened successfully.
 384	 */
 385	if (dad)
 386		depth = initial_depth = 1;
 387
 388	root = dad;
 389	nps[depth] = dad;
 390
 391	for (offset = 0;
 392	     offset >= 0 && depth >= initial_depth;
 393	     offset = fdt_next_node(blob, offset, &depth)) {
 394		if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
 395			continue;
 396
 397		if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
 398		    !of_fdt_device_is_available(blob, offset))
 399			continue;
 400
 401		if (!populate_node(blob, offset, &mem, nps[depth],
 402				   &nps[depth+1], dryrun))
 403			return mem - base;
 404
 405		if (!dryrun && nodepp && !*nodepp)
 406			*nodepp = nps[depth+1];
 407		if (!dryrun && !root)
 408			root = nps[depth+1];
 409	}
 410
 411	if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 412		pr_err("Error %d processing FDT\n", offset);
 413		return -EINVAL;
 414	}
 415
 416	/*
 417	 * Reverse the child list. Some drivers assumes node order matches .dts
 418	 * node order
 419	 */
 420	if (!dryrun)
 421		reverse_nodes(root);
 422
 423	return mem - base;
 424}
 425
 426/**
 427 * __unflatten_device_tree - create tree of device_nodes from flat blob
 428 *
 429 * unflattens a device-tree, creating the
 430 * tree of struct device_node. It also fills the "name" and "type"
 431 * pointers of the nodes so the normal device-tree walking functions
 432 * can be used.
 433 * @blob: The blob to expand
 434 * @dad: Parent device node
 435 * @mynodes: The device_node tree created by the call
 436 * @dt_alloc: An allocator that provides a virtual address to memory
 437 * for the resulting tree
 438 * @detached: if true set OF_DETACHED on @mynodes
 439 *
 440 * Returns NULL on failure or the memory chunk containing the unflattened
 441 * device tree on success.
 442 */
 443void *__unflatten_device_tree(const void *blob,
 444			      struct device_node *dad,
 445			      struct device_node **mynodes,
 446			      void *(*dt_alloc)(u64 size, u64 align),
 447			      bool detached)
 448{
 449	int size;
 450	void *mem;
 451
 452	pr_debug(" -> unflatten_device_tree()\n");
 453
 454	if (!blob) {
 455		pr_debug("No device tree pointer\n");
 456		return NULL;
 457	}
 458
 459	pr_debug("Unflattening device tree:\n");
 460	pr_debug("magic: %08x\n", fdt_magic(blob));
 461	pr_debug("size: %08x\n", fdt_totalsize(blob));
 462	pr_debug("version: %08x\n", fdt_version(blob));
 463
 464	if (fdt_check_header(blob)) {
 465		pr_err("Invalid device tree blob header\n");
 466		return NULL;
 467	}
 468
 469	/* First pass, scan for size */
 470	size = unflatten_dt_nodes(blob, NULL, dad, NULL);
 471	if (size < 0)
 472		return NULL;
 473
 474	size = ALIGN(size, 4);
 475	pr_debug("  size is %d, allocating...\n", size);
 476
 477	/* Allocate memory for the expanded device tree */
 478	mem = dt_alloc(size + 4, __alignof__(struct device_node));
 479	if (!mem)
 480		return NULL;
 481
 482	memset(mem, 0, size);
 483
 484	*(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 485
 486	pr_debug("  unflattening %p...\n", mem);
 487
 488	/* Second pass, do actual unflattening */
 489	unflatten_dt_nodes(blob, mem, dad, mynodes);
 490	if (be32_to_cpup(mem + size) != 0xdeadbeef)
 491		pr_warning("End of tree marker overwritten: %08x\n",
 492			   be32_to_cpup(mem + size));
 493
 494	if (detached && mynodes) {
 495		of_node_set_flag(*mynodes, OF_DETACHED);
 496		pr_debug("unflattened tree is detached\n");
 497	}
 498
 499	pr_debug(" <- unflatten_device_tree()\n");
 500	return mem;
 501}
 502
 503static void *kernel_tree_alloc(u64 size, u64 align)
 504{
 505	return kzalloc(size, GFP_KERNEL);
 506}
 507
 508static DEFINE_MUTEX(of_fdt_unflatten_mutex);
 509
 510/**
 511 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 512 * @blob: Flat device tree blob
 513 * @dad: Parent device node
 514 * @mynodes: The device tree created by the call
 515 *
 516 * unflattens the device-tree passed by the firmware, creating the
 517 * tree of struct device_node. It also fills the "name" and "type"
 518 * pointers of the nodes so the normal device-tree walking functions
 519 * can be used.
 520 *
 521 * Returns NULL on failure or the memory chunk containing the unflattened
 522 * device tree on success.
 523 */
 524void *of_fdt_unflatten_tree(const unsigned long *blob,
 525			    struct device_node *dad,
 526			    struct device_node **mynodes)
 527{
 528	void *mem;
 529
 530	mutex_lock(&of_fdt_unflatten_mutex);
 531	mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
 532				      true);
 533	mutex_unlock(&of_fdt_unflatten_mutex);
 534
 535	return mem;
 536}
 537EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 538
 539/* Everything below here references initial_boot_params directly. */
 540int __initdata dt_root_addr_cells;
 541int __initdata dt_root_size_cells;
 542
 543void *initial_boot_params;
 544
 545#ifdef CONFIG_OF_EARLY_FLATTREE
 546
 547static u32 of_fdt_crc32;
 548
 549/**
 550 * res_mem_reserve_reg() - reserve all memory described in 'reg' property
 551 */
 552static int __init __reserved_mem_reserve_reg(unsigned long node,
 553					     const char *uname)
 554{
 555	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 556	phys_addr_t base, size;
 557	int len;
 558	const __be32 *prop;
 559	int nomap, first = 1;
 
 560
 561	prop = of_get_flat_dt_prop(node, "reg", &len);
 562	if (!prop)
 563		return -ENOENT;
 564
 565	if (len && len % t_len != 0) {
 566		pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 567		       uname);
 568		return -EINVAL;
 569	}
 570
 571	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 572
 573	while (len >= t_len) {
 574		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 575		size = dt_mem_next_cell(dt_root_size_cells, &prop);
 576
 577		if (size &&
 578		    early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 579			pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 580				uname, &base, (unsigned long)size / SZ_1M);
 581		else
 582			pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 583				uname, &base, (unsigned long)size / SZ_1M);
 584
 585		len -= t_len;
 586		if (first) {
 587			fdt_reserved_mem_save_node(node, uname, base, size);
 588			first = 0;
 589		}
 590	}
 591	return 0;
 592}
 593
 594/**
 595 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 596 * in /reserved-memory matches the values supported by the current implementation,
 597 * also check if ranges property has been provided
 598 */
 599static int __init __reserved_mem_check_root(unsigned long node)
 600{
 601	const __be32 *prop;
 602
 603	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 604	if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 605		return -EINVAL;
 606
 607	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 608	if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 609		return -EINVAL;
 610
 611	prop = of_get_flat_dt_prop(node, "ranges", NULL);
 612	if (!prop)
 613		return -EINVAL;
 614	return 0;
 615}
 616
 617/**
 618 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 619 */
 620static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 621					  int depth, void *data)
 622{
 623	static int found;
 624	int err;
 625
 626	if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 627		if (__reserved_mem_check_root(node) != 0) {
 628			pr_err("Reserved memory: unsupported node format, ignoring\n");
 629			/* break scan */
 630			return 1;
 631		}
 632		found = 1;
 633		/* scan next node */
 634		return 0;
 635	} else if (!found) {
 636		/* scan next node */
 637		return 0;
 638	} else if (found && depth < 2) {
 639		/* scanning of /reserved-memory has been finished */
 640		return 1;
 641	}
 642
 643	if (!of_fdt_device_is_available(initial_boot_params, node))
 644		return 0;
 645
 646	err = __reserved_mem_reserve_reg(node, uname);
 647	if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 648		fdt_reserved_mem_save_node(node, uname, 0, 0);
 649
 650	/* scan next node */
 651	return 0;
 652}
 653
 654/**
 655 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 656 *
 657 * This function grabs memory from early allocator for device exclusive use
 658 * defined in device tree structures. It should be called by arch specific code
 659 * once the early allocator (i.e. memblock) has been fully activated.
 660 */
 661void __init early_init_fdt_scan_reserved_mem(void)
 662{
 663	int n;
 664	u64 base, size;
 665
 666	if (!initial_boot_params)
 667		return;
 668
 669	/* Process header /memreserve/ fields */
 670	for (n = 0; ; n++) {
 671		fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 672		if (!size)
 673			break;
 674		early_init_dt_reserve_memory_arch(base, size, 0);
 675	}
 676
 677	of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 678	fdt_init_reserved_mem();
 679}
 680
 681/**
 682 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
 683 */
 684void __init early_init_fdt_reserve_self(void)
 685{
 686	if (!initial_boot_params)
 687		return;
 688
 689	/* Reserve the dtb region */
 690	early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
 691					  fdt_totalsize(initial_boot_params),
 692					  0);
 693}
 694
 695/**
 696 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 697 * @it: callback function
 698 * @data: context data pointer
 699 *
 700 * This function is used to scan the flattened device-tree, it is
 701 * used to extract the memory information at boot before we can
 702 * unflatten the tree
 703 */
 704int __init of_scan_flat_dt(int (*it)(unsigned long node,
 705				     const char *uname, int depth,
 706				     void *data),
 707			   void *data)
 708{
 709	const void *blob = initial_boot_params;
 710	const char *pathp;
 711	int offset, rc = 0, depth = -1;
 712
 713	if (!blob)
 714		return 0;
 715
 716	for (offset = fdt_next_node(blob, -1, &depth);
 717	     offset >= 0 && depth >= 0 && !rc;
 718	     offset = fdt_next_node(blob, offset, &depth)) {
 719
 720		pathp = fdt_get_name(blob, offset, NULL);
 721		if (*pathp == '/')
 722			pathp = kbasename(pathp);
 723		rc = it(offset, pathp, depth, data);
 724	}
 725	return rc;
 726}
 727
 728/**
 729 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
 730 * @it: callback function
 731 * @data: context data pointer
 732 *
 733 * This function is used to scan sub-nodes of a node.
 734 */
 735int __init of_scan_flat_dt_subnodes(unsigned long parent,
 736				    int (*it)(unsigned long node,
 737					      const char *uname,
 738					      void *data),
 739				    void *data)
 740{
 741	const void *blob = initial_boot_params;
 742	int node;
 743
 744	fdt_for_each_subnode(node, blob, parent) {
 745		const char *pathp;
 746		int rc;
 747
 748		pathp = fdt_get_name(blob, node, NULL);
 749		if (*pathp == '/')
 750			pathp = kbasename(pathp);
 751		rc = it(node, pathp, data);
 752		if (rc)
 753			return rc;
 754	}
 755	return 0;
 756}
 757
 758/**
 759 * of_get_flat_dt_subnode_by_name - get the subnode by given name
 760 *
 761 * @node: the parent node
 762 * @uname: the name of subnode
 763 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
 764 */
 765
 766int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
 767{
 768	return fdt_subnode_offset(initial_boot_params, node, uname);
 769}
 770
 771/**
 772 * of_get_flat_dt_root - find the root node in the flat blob
 773 */
 774unsigned long __init of_get_flat_dt_root(void)
 775{
 776	return 0;
 777}
 778
 779/**
 780 * of_get_flat_dt_size - Return the total size of the FDT
 781 */
 782int __init of_get_flat_dt_size(void)
 783{
 784	return fdt_totalsize(initial_boot_params);
 785}
 786
 787/**
 788 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 789 *
 790 * This function can be used within scan_flattened_dt callback to get
 791 * access to properties
 792 */
 793const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 794				       int *size)
 795{
 796	return fdt_getprop(initial_boot_params, node, name, size);
 797}
 798
 799/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 800 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 801 * @node: node to test
 802 * @compat: compatible string to compare with compatible list.
 803 */
 804int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 805{
 806	return of_fdt_is_compatible(initial_boot_params, node, compat);
 807}
 808
 809/**
 810 * of_flat_dt_match - Return true if node matches a list of compatible values
 811 */
 812int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 813{
 814	return of_fdt_match(initial_boot_params, node, compat);
 
 
 
 
 
 
 
 
 
 
 
 
 815}
 816
 817/**
 818 * of_get_flat_dt_prop - Given a node in the flat blob, return the phandle
 819 */
 820uint32_t __init of_get_flat_dt_phandle(unsigned long node)
 821{
 822	return fdt_get_phandle(initial_boot_params, node);
 823}
 824
 825struct fdt_scan_status {
 826	const char *name;
 827	int namelen;
 828	int depth;
 829	int found;
 830	int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 831	void *data;
 832};
 833
 834const char * __init of_flat_dt_get_machine_name(void)
 835{
 836	const char *name;
 837	unsigned long dt_root = of_get_flat_dt_root();
 838
 839	name = of_get_flat_dt_prop(dt_root, "model", NULL);
 840	if (!name)
 841		name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 842	return name;
 843}
 844
 845/**
 846 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 847 *
 848 * @default_match: A machine specific ptr to return in case of no match.
 849 * @get_next_compat: callback function to return next compatible match table.
 850 *
 851 * Iterate through machine match tables to find the best match for the machine
 852 * compatible string in the FDT.
 853 */
 854const void * __init of_flat_dt_match_machine(const void *default_match,
 855		const void * (*get_next_compat)(const char * const**))
 856{
 857	const void *data = NULL;
 858	const void *best_data = default_match;
 859	const char *const *compat;
 860	unsigned long dt_root;
 861	unsigned int best_score = ~1, score = 0;
 862
 863	dt_root = of_get_flat_dt_root();
 864	while ((data = get_next_compat(&compat))) {
 865		score = of_flat_dt_match(dt_root, compat);
 866		if (score > 0 && score < best_score) {
 867			best_data = data;
 868			best_score = score;
 869		}
 870	}
 871	if (!best_data) {
 872		const char *prop;
 873		int size;
 874
 875		pr_err("\n unrecognized device tree list:\n[ ");
 876
 877		prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 878		if (prop) {
 879			while (size > 0) {
 880				printk("'%s' ", prop);
 881				size -= strlen(prop) + 1;
 882				prop += strlen(prop) + 1;
 883			}
 884		}
 885		printk("]\n\n");
 886		return NULL;
 887	}
 888
 889	pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 890
 891	return best_data;
 892}
 893
 894#ifdef CONFIG_BLK_DEV_INITRD
 895#ifndef __early_init_dt_declare_initrd
 896static void __early_init_dt_declare_initrd(unsigned long start,
 897					   unsigned long end)
 898{
 899	initrd_start = (unsigned long)__va(start);
 900	initrd_end = (unsigned long)__va(end);
 901	initrd_below_start_ok = 1;
 
 
 
 
 
 
 
 902}
 903#endif
 904
 905/**
 906 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 907 * @node: reference to node containing initrd location ('chosen')
 908 */
 909static void __init early_init_dt_check_for_initrd(unsigned long node)
 910{
 911	u64 start, end;
 912	int len;
 913	const __be32 *prop;
 914
 915	pr_debug("Looking for initrd properties... ");
 916
 917	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 918	if (!prop)
 919		return;
 920	start = of_read_number(prop, len/4);
 921
 922	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 923	if (!prop)
 924		return;
 925	end = of_read_number(prop, len/4);
 926
 927	__early_init_dt_declare_initrd(start, end);
 
 
 928
 929	pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 930		 (unsigned long long)start, (unsigned long long)end);
 931}
 932#else
 933static inline void early_init_dt_check_for_initrd(unsigned long node)
 934{
 935}
 936#endif /* CONFIG_BLK_DEV_INITRD */
 937
 938#ifdef CONFIG_SERIAL_EARLYCON
 939
 940int __init early_init_dt_scan_chosen_stdout(void)
 941{
 942	int offset;
 943	const char *p, *q, *options = NULL;
 944	int l;
 945	const struct earlycon_id **p_match;
 946	const void *fdt = initial_boot_params;
 947
 948	offset = fdt_path_offset(fdt, "/chosen");
 949	if (offset < 0)
 950		offset = fdt_path_offset(fdt, "/chosen@0");
 951	if (offset < 0)
 952		return -ENOENT;
 953
 954	p = fdt_getprop(fdt, offset, "stdout-path", &l);
 955	if (!p)
 956		p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 957	if (!p || !l)
 958		return -ENOENT;
 959
 960	q = strchrnul(p, ':');
 961	if (*q != '\0')
 962		options = q + 1;
 963	l = q - p;
 964
 965	/* Get the node specified by stdout-path */
 966	offset = fdt_path_offset_namelen(fdt, p, l);
 967	if (offset < 0) {
 968		pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
 969		return 0;
 970	}
 971
 972	for (p_match = __earlycon_table; p_match < __earlycon_table_end;
 973	     p_match++) {
 974		const struct earlycon_id *match = *p_match;
 975
 976		if (!match->compatible[0])
 977			continue;
 978
 979		if (fdt_node_check_compatible(fdt, offset, match->compatible))
 980			continue;
 981
 982		of_setup_earlycon(match, offset, options);
 983		return 0;
 984	}
 985	return -ENODEV;
 986}
 987#endif
 988
 989/**
 990 * early_init_dt_scan_root - fetch the top level address and size cells
 991 */
 992int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 993				   int depth, void *data)
 994{
 995	const __be32 *prop;
 996
 997	if (depth != 0)
 998		return 0;
 999
1000	dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
1001	dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
1002
1003	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
1004	if (prop)
1005		dt_root_size_cells = be32_to_cpup(prop);
1006	pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
1007
1008	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
1009	if (prop)
1010		dt_root_addr_cells = be32_to_cpup(prop);
1011	pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
1012
1013	/* break now */
1014	return 1;
1015}
1016
1017u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
1018{
1019	const __be32 *p = *cellp;
1020
1021	*cellp = p + s;
1022	return of_read_number(p, s);
1023}
1024
1025/**
1026 * early_init_dt_scan_memory - Look for and parse memory nodes
1027 */
1028int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
1029				     int depth, void *data)
1030{
1031	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
1032	const __be32 *reg, *endp;
1033	int l;
1034	bool hotpluggable;
1035
1036	/* We are scanning "memory" nodes only */
1037	if (type == NULL) {
1038		/*
1039		 * The longtrail doesn't have a device_type on the
1040		 * /memory node, so look for the node called /memory@0.
1041		 */
1042		if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0)
1043			return 0;
1044	} else if (strcmp(type, "memory") != 0)
1045		return 0;
1046
1047	reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1048	if (reg == NULL)
1049		reg = of_get_flat_dt_prop(node, "reg", &l);
1050	if (reg == NULL)
1051		return 0;
1052
1053	endp = reg + (l / sizeof(__be32));
1054	hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1055
1056	pr_debug("memory scan node %s, reg size %d,\n", uname, l);
1057
1058	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1059		u64 base, size;
1060
1061		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
1062		size = dt_mem_next_cell(dt_root_size_cells, &reg);
1063
1064		if (size == 0)
1065			continue;
1066		pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
1067		    (unsigned long long)size);
1068
1069		early_init_dt_add_memory_arch(base, size);
1070
1071		if (!hotpluggable)
1072			continue;
1073
1074		if (early_init_dt_mark_hotplug_memory_arch(base, size))
1075			pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1076				base, base + size);
1077	}
1078
1079	return 0;
1080}
1081
1082int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
1083				     int depth, void *data)
1084{
1085	int l;
1086	const char *p;
 
1087
1088	pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
1089
1090	if (depth != 1 || !data ||
1091	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
1092		return 0;
1093
1094	early_init_dt_check_for_initrd(node);
1095
1096	/* Retrieve command line */
1097	p = of_get_flat_dt_prop(node, "bootargs", &l);
1098	if (p != NULL && l > 0)
1099		strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
1100
1101	/*
1102	 * CONFIG_CMDLINE is meant to be a default in case nothing else
1103	 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1104	 * is set in which case we override whatever was found earlier.
1105	 */
1106#ifdef CONFIG_CMDLINE
1107#if defined(CONFIG_CMDLINE_EXTEND)
1108	strlcat(data, " ", COMMAND_LINE_SIZE);
1109	strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1110#elif defined(CONFIG_CMDLINE_FORCE)
1111	strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1112#else
1113	/* No arguments from boot loader, use kernel's  cmdl*/
1114	if (!((char *)data)[0])
1115		strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1116#endif
1117#endif /* CONFIG_CMDLINE */
1118
1119	pr_debug("Command line is: %s\n", (char*)data);
 
 
 
 
 
 
 
 
 
 
 
 
1120
1121	/* break now */
1122	return 1;
1123}
1124
1125#ifdef CONFIG_HAVE_MEMBLOCK
1126#ifndef MIN_MEMBLOCK_ADDR
1127#define MIN_MEMBLOCK_ADDR	__pa(PAGE_OFFSET)
1128#endif
1129#ifndef MAX_MEMBLOCK_ADDR
1130#define MAX_MEMBLOCK_ADDR	((phys_addr_t)~0)
1131#endif
1132
1133void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1134{
1135	const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1136
 
 
 
 
 
 
1137	if (!PAGE_ALIGNED(base)) {
1138		if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1139			pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1140				base, base + size);
1141			return;
1142		}
1143		size -= PAGE_SIZE - (base & ~PAGE_MASK);
1144		base = PAGE_ALIGN(base);
1145	}
1146	size &= PAGE_MASK;
1147
1148	if (base > MAX_MEMBLOCK_ADDR) {
1149		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1150				base, base + size);
1151		return;
1152	}
1153
1154	if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1155		pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1156				((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1157		size = MAX_MEMBLOCK_ADDR - base + 1;
1158	}
1159
1160	if (base + size < phys_offset) {
1161		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1162			   base, base + size);
1163		return;
1164	}
1165	if (base < phys_offset) {
1166		pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1167			   base, phys_offset);
1168		size -= phys_offset - base;
1169		base = phys_offset;
1170	}
1171	memblock_add(base, size);
1172}
1173
1174int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1175{
1176	return memblock_mark_hotplug(base, size);
1177}
1178
1179int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1180					phys_addr_t size, bool nomap)
1181{
1182	if (nomap)
1183		return memblock_remove(base, size);
1184	return memblock_reserve(base, size);
1185}
1186
1187#else
1188void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1189{
1190	WARN_ON(1);
1191}
1192
1193int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1194{
1195	return -ENOSYS;
1196}
1197
1198int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1199					phys_addr_t size, bool nomap)
1200{
1201	pr_err("Reserved memory not supported, ignoring range %pa - %pa%s\n",
1202		  &base, &size, nomap ? " (nomap)" : "");
1203	return -ENOSYS;
1204}
1205#endif
1206
1207static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1208{
1209	return memblock_virt_alloc(size, align);
1210}
1211
1212bool __init early_init_dt_verify(void *params)
1213{
1214	if (!params)
1215		return false;
1216
1217	/* check device tree validity */
1218	if (fdt_check_header(params))
1219		return false;
1220
1221	/* Setup flat device-tree pointer */
1222	initial_boot_params = params;
1223	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1224				fdt_totalsize(initial_boot_params));
1225	return true;
1226}
1227
1228
1229void __init early_init_dt_scan_nodes(void)
1230{
 
 
1231	/* Retrieve various information from the /chosen node */
1232	of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
 
 
1233
1234	/* Initialize {size,address}-cells info */
1235	of_scan_flat_dt(early_init_dt_scan_root, NULL);
1236
1237	/* Setup memory, calling early_init_dt_add_memory_arch */
1238	of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1239}
1240
1241bool __init early_init_dt_scan(void *params)
1242{
1243	bool status;
1244
1245	status = early_init_dt_verify(params);
1246	if (!status)
1247		return false;
1248
1249	early_init_dt_scan_nodes();
1250	return true;
1251}
1252
1253/**
1254 * unflatten_device_tree - create tree of device_nodes from flat blob
1255 *
1256 * unflattens the device-tree passed by the firmware, creating the
1257 * tree of struct device_node. It also fills the "name" and "type"
1258 * pointers of the nodes so the normal device-tree walking functions
1259 * can be used.
1260 */
1261void __init unflatten_device_tree(void)
1262{
1263	__unflatten_device_tree(initial_boot_params, NULL, &of_root,
1264				early_init_dt_alloc_memory_arch, false);
1265
1266	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1267	of_alias_scan(early_init_dt_alloc_memory_arch);
1268
1269	unittest_unflatten_overlay_base();
1270}
1271
1272/**
1273 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1274 *
1275 * Copies and unflattens the device-tree passed by the firmware, creating the
1276 * tree of struct device_node. It also fills the "name" and "type"
1277 * pointers of the nodes so the normal device-tree walking functions
1278 * can be used. This should only be used when the FDT memory has not been
1279 * reserved such is the case when the FDT is built-in to the kernel init
1280 * section. If the FDT memory is reserved already then unflatten_device_tree
1281 * should be used instead.
1282 */
1283void __init unflatten_and_copy_device_tree(void)
1284{
1285	int size;
1286	void *dt;
1287
1288	if (!initial_boot_params) {
1289		pr_warn("No valid device tree found, continuing without\n");
1290		return;
1291	}
1292
1293	size = fdt_totalsize(initial_boot_params);
1294	dt = early_init_dt_alloc_memory_arch(size,
1295					     roundup_pow_of_two(FDT_V17_SIZE));
1296
1297	if (dt) {
1298		memcpy(dt, initial_boot_params, size);
1299		initial_boot_params = dt;
1300	}
1301	unflatten_device_tree();
1302}
1303
1304#ifdef CONFIG_SYSFS
1305static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1306			       struct bin_attribute *bin_attr,
1307			       char *buf, loff_t off, size_t count)
1308{
1309	memcpy(buf, initial_boot_params + off, count);
1310	return count;
1311}
1312
1313static int __init of_fdt_raw_init(void)
1314{
1315	static struct bin_attribute of_fdt_raw_attr =
1316		__BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1317
1318	if (!initial_boot_params)
1319		return 0;
1320
1321	if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1322				     fdt_totalsize(initial_boot_params))) {
1323		pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1324		return 0;
1325	}
1326	of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1327	return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1328}
1329late_initcall(of_fdt_raw_init);
1330#endif
1331
1332#endif /* CONFIG_OF_EARLY_FLATTREE */