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v6.13.7
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Functions for working with the Flattened Device Tree data format
   4 *
   5 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
   6 * benh@kernel.crashing.org
 
 
 
 
   7 */
   8
   9#define pr_fmt(fmt)	"OF: fdt: " fmt
  10
  11#include <linux/crash_dump.h>
  12#include <linux/crc32.h>
  13#include <linux/kernel.h>
  14#include <linux/initrd.h>
  15#include <linux/memblock.h>
  16#include <linux/mutex.h>
  17#include <linux/of.h>
  18#include <linux/of_fdt.h>
 
  19#include <linux/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 * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by
  36 * cmd_wrap_S_dtb in scripts/Makefile.dtbs
  37 */
  38extern uint8_t __dtb_empty_root_begin[];
  39extern uint8_t __dtb_empty_root_end[];
  40
  41/*
  42 * of_fdt_limit_memory - limit the number of regions in the /memory node
  43 * @limit: maximum entries
  44 *
  45 * Adjust the flattened device tree to have at most 'limit' number of
  46 * memory entries in the /memory node. This function may be called
  47 * any time after initial_boot_param is set.
  48 */
  49void __init of_fdt_limit_memory(int limit)
  50{
  51	int memory;
  52	int len;
  53	const void *val;
  54	int cell_size = sizeof(uint32_t)*(dt_root_addr_cells + dt_root_size_cells);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  55
  56	memory = fdt_path_offset(initial_boot_params, "/memory");
  57	if (memory > 0) {
  58		val = fdt_getprop(initial_boot_params, memory, "reg", &len);
  59		if (len > limit*cell_size) {
  60			len = limit*cell_size;
  61			pr_debug("Limiting number of entries to %d\n", limit);
  62			fdt_setprop(initial_boot_params, memory, "reg", val,
  63					len);
  64		}
  65	}
  66}
  67
  68bool of_fdt_device_is_available(const void *blob, unsigned long node)
 
 
 
 
 
 
 
 
 
 
 
  69{
  70	const char *status = fdt_getprop(blob, node, "status", NULL);
 
 
  71
  72	if (!status)
  73		return true;
 
 
 
 
 
 
 
 
 
  74
  75	if (!strcmp(status, "ok") || !strcmp(status, "okay"))
  76		return true;
  77
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  78	return false;
  79}
  80
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  81static void *unflatten_dt_alloc(void **mem, unsigned long size,
  82				       unsigned long align)
  83{
  84	void *res;
  85
  86	*mem = PTR_ALIGN(*mem, align);
  87	res = *mem;
  88	*mem += size;
  89
  90	return res;
  91}
  92
  93static void populate_properties(const void *blob,
  94				int offset,
  95				void **mem,
  96				struct device_node *np,
  97				const char *nodename,
 
 
 
 
 
 
 
 
 
 
 
 
  98				bool dryrun)
  99{
 100	struct property *pp, **pprev = NULL;
 101	int cur;
 102	bool has_name = false;
 103
 104	pprev = &np->properties;
 105	for (cur = fdt_first_property_offset(blob, offset);
 106	     cur >= 0;
 107	     cur = fdt_next_property_offset(blob, cur)) {
 108		const __be32 *val;
 109		const char *pname;
 110		u32 sz;
 111
 112		val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
 113		if (!val) {
 114			pr_warn("Cannot locate property at 0x%x\n", cur);
 115			continue;
 116		}
 117
 118		if (!pname) {
 119			pr_warn("Cannot find property name at 0x%x\n", cur);
 120			continue;
 121		}
 122
 123		if (!strcmp(pname, "name"))
 124			has_name = true;
 125
 126		pp = unflatten_dt_alloc(mem, sizeof(struct property),
 127					__alignof__(struct property));
 128		if (dryrun)
 129			continue;
 130
 131		/* We accept flattened tree phandles either in
 132		 * ePAPR-style "phandle" properties, or the
 133		 * legacy "linux,phandle" properties.  If both
 134		 * appear and have different values, things
 135		 * will get weird. Don't do that.
 136		 */
 137		if (!strcmp(pname, "phandle") ||
 138		    !strcmp(pname, "linux,phandle")) {
 139			if (!np->phandle)
 140				np->phandle = be32_to_cpup(val);
 141		}
 142
 143		/* And we process the "ibm,phandle" property
 144		 * used in pSeries dynamic device tree
 145		 * stuff
 146		 */
 147		if (!strcmp(pname, "ibm,phandle"))
 148			np->phandle = be32_to_cpup(val);
 149
 150		pp->name   = (char *)pname;
 151		pp->length = sz;
 152		pp->value  = (__be32 *)val;
 153		*pprev     = pp;
 154		pprev      = &pp->next;
 155	}
 156
 157	/* With version 0x10 we may not have the name property,
 158	 * recreate it here from the unit name if absent
 159	 */
 160	if (!has_name) {
 161		const char *p = nodename, *ps = p, *pa = NULL;
 162		int len;
 163
 164		while (*p) {
 165			if ((*p) == '@')
 166				pa = p;
 167			else if ((*p) == '/')
 168				ps = p + 1;
 169			p++;
 170		}
 171
 172		if (pa < ps)
 173			pa = p;
 174		len = (pa - ps) + 1;
 175		pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
 176					__alignof__(struct property));
 177		if (!dryrun) {
 178			pp->name   = "name";
 179			pp->length = len;
 180			pp->value  = pp + 1;
 181			*pprev     = pp;
 182			memcpy(pp->value, ps, len - 1);
 183			((char *)pp->value)[len - 1] = 0;
 184			pr_debug("fixed up name for %s -> %s\n",
 185				 nodename, (char *)pp->value);
 186		}
 187	}
 188}
 189
 190static int populate_node(const void *blob,
 191			  int offset,
 192			  void **mem,
 193			  struct device_node *dad,
 194			  struct device_node **pnp,
 195			  bool dryrun)
 196{
 197	struct device_node *np;
 
 198	const char *pathp;
 199	int len;
 
 
 
 
 
 200
 201	pathp = fdt_get_name(blob, offset, &len);
 202	if (!pathp) {
 203		*pnp = NULL;
 204		return len;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 205	}
 206
 207	len++;
 208
 209	np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len,
 210				__alignof__(struct device_node));
 211	if (!dryrun) {
 212		char *fn;
 213		of_node_init(np);
 214		np->full_name = fn = ((char *)np) + sizeof(*np);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 215
 216		memcpy(fn, pathp, len);
 217
 218		if (dad != NULL) {
 219			np->parent = dad;
 220			np->sibling = dad->child;
 221			dad->child = np;
 222		}
 223	}
 
 
 
 
 
 
 224
 225	populate_properties(blob, offset, mem, np, pathp, dryrun);
 226	if (!dryrun) {
 227		np->name = of_get_property(np, "name", NULL);
 228		if (!np->name)
 229			np->name = "<NULL>";
 230	}
 231
 232	*pnp = np;
 233	return 0;
 234}
 235
 236static void reverse_nodes(struct device_node *parent)
 237{
 238	struct device_node *child, *next;
 239
 240	/* In-depth first */
 241	child = parent->child;
 242	while (child) {
 243		reverse_nodes(child);
 244
 245		child = child->sibling;
 246	}
 247
 248	/* Reverse the nodes in the child list */
 249	child = parent->child;
 250	parent->child = NULL;
 251	while (child) {
 252		next = child->sibling;
 253
 254		child->sibling = parent->child;
 255		parent->child = child;
 256		child = next;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 257	}
 258}
 259
 260/**
 261 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
 262 * @blob: The parent device tree blob
 263 * @mem: Memory chunk to use for allocating device nodes and properties
 264 * @dad: Parent struct device_node
 265 * @nodepp: The device_node tree created by the call
 266 *
 267 * Return: The size of unflattened device tree or error code
 268 */
 269static int unflatten_dt_nodes(const void *blob,
 270			      void *mem,
 271			      struct device_node *dad,
 272			      struct device_node **nodepp)
 273{
 274	struct device_node *root;
 275	int offset = 0, depth = 0, initial_depth = 0;
 276#define FDT_MAX_DEPTH	64
 277	struct device_node *nps[FDT_MAX_DEPTH];
 278	void *base = mem;
 279	bool dryrun = !base;
 280	int ret;
 281
 282	if (nodepp)
 283		*nodepp = NULL;
 284
 285	/*
 286	 * We're unflattening device sub-tree if @dad is valid. There are
 287	 * possibly multiple nodes in the first level of depth. We need
 288	 * set @depth to 1 to make fdt_next_node() happy as it bails
 289	 * immediately when negative @depth is found. Otherwise, the device
 290	 * nodes except the first one won't be unflattened successfully.
 291	 */
 292	if (dad)
 293		depth = initial_depth = 1;
 294
 295	root = dad;
 296	nps[depth] = dad;
 297
 298	for (offset = 0;
 299	     offset >= 0 && depth >= initial_depth;
 300	     offset = fdt_next_node(blob, offset, &depth)) {
 301		if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1))
 302			continue;
 303
 304		if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
 305		    !of_fdt_device_is_available(blob, offset))
 306			continue;
 307
 308		ret = populate_node(blob, offset, &mem, nps[depth],
 309				   &nps[depth+1], dryrun);
 310		if (ret < 0)
 311			return ret;
 312
 313		if (!dryrun && nodepp && !*nodepp)
 314			*nodepp = nps[depth+1];
 315		if (!dryrun && !root)
 316			root = nps[depth+1];
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 317	}
 
 
 
 
 318
 319	if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 320		pr_err("Error %d processing FDT\n", offset);
 321		return -EINVAL;
 
 322	}
 323
 
 
 
 
 
 
 
 
 
 
 
 324	/*
 325	 * Reverse the child list. Some drivers assumes node order matches .dts
 326	 * node order
 327	 */
 328	if (!dryrun)
 329		reverse_nodes(root);
 
 
 
 
 
 
 
 
 330
 331	return mem - base;
 
 
 
 332}
 333
 334/**
 335 * __unflatten_device_tree - create tree of device_nodes from flat blob
 
 
 
 
 
 336 * @blob: The blob to expand
 337 * @dad: Parent device node
 338 * @mynodes: The device_node tree created by the call
 339 * @dt_alloc: An allocator that provides a virtual address to memory
 340 * for the resulting tree
 341 * @detached: if true set OF_DETACHED on @mynodes
 342 *
 343 * unflattens a device-tree, creating the tree of struct device_node. It also
 344 * fills the "name" and "type" pointers of the nodes so the normal device-tree
 345 * walking functions can be used.
 346 *
 347 * Return: NULL on failure or the memory chunk containing the unflattened
 348 * device tree on success.
 349 */
 350void *__unflatten_device_tree(const void *blob,
 351			      struct device_node *dad,
 352			      struct device_node **mynodes,
 353			      void *(*dt_alloc)(u64 size, u64 align),
 354			      bool detached)
 355{
 356	int size;
 
 357	void *mem;
 358	int ret;
 359
 360	if (mynodes)
 361		*mynodes = NULL;
 362
 363	pr_debug(" -> unflatten_device_tree()\n");
 364
 365	if (!blob) {
 366		pr_debug("No device tree pointer\n");
 367		return NULL;
 368	}
 369
 370	pr_debug("Unflattening device tree:\n");
 371	pr_debug("magic: %08x\n", fdt_magic(blob));
 372	pr_debug("size: %08x\n", fdt_totalsize(blob));
 373	pr_debug("version: %08x\n", fdt_version(blob));
 374
 375	if (fdt_check_header(blob)) {
 376		pr_err("Invalid device tree blob header\n");
 377		return NULL;
 378	}
 379
 380	/* First pass, scan for size */
 381	size = unflatten_dt_nodes(blob, NULL, dad, NULL);
 382	if (size <= 0)
 383		return NULL;
 384
 385	size = ALIGN(size, 4);
 386	pr_debug("  size is %d, allocating...\n", size);
 
 387
 388	/* Allocate memory for the expanded device tree */
 389	mem = dt_alloc(size + 4, __alignof__(struct device_node));
 390	if (!mem)
 391		return NULL;
 392
 393	memset(mem, 0, size);
 394
 395	*(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 396
 397	pr_debug("  unflattening %p...\n", mem);
 398
 399	/* Second pass, do actual unflattening */
 400	ret = unflatten_dt_nodes(blob, mem, dad, mynodes);
 401
 402	if (be32_to_cpup(mem + size) != 0xdeadbeef)
 403		pr_warn("End of tree marker overwritten: %08x\n",
 404			be32_to_cpup(mem + size));
 405
 406	if (ret <= 0)
 407		return NULL;
 408
 409	if (detached && mynodes && *mynodes) {
 410		of_node_set_flag(*mynodes, OF_DETACHED);
 411		pr_debug("unflattened tree is detached\n");
 412	}
 413
 414	pr_debug(" <- unflatten_device_tree()\n");
 415	return mem;
 416}
 417
 418static void *kernel_tree_alloc(u64 size, u64 align)
 419{
 420	return kzalloc(size, GFP_KERNEL);
 421}
 422
 423static DEFINE_MUTEX(of_fdt_unflatten_mutex);
 424
 425/**
 426 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 427 * @blob: Flat device tree blob
 428 * @dad: Parent device node
 429 * @mynodes: The device tree created by the call
 430 *
 431 * unflattens the device-tree passed by the firmware, creating the
 432 * tree of struct device_node. It also fills the "name" and "type"
 433 * pointers of the nodes so the normal device-tree walking functions
 434 * can be used.
 435 *
 436 * Return: NULL on failure or the memory chunk containing the unflattened
 437 * device tree on success.
 438 */
 439void *of_fdt_unflatten_tree(const unsigned long *blob,
 440			    struct device_node *dad,
 441			    struct device_node **mynodes)
 442{
 443	void *mem;
 444
 445	mutex_lock(&of_fdt_unflatten_mutex);
 446	mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
 447				      true);
 448	mutex_unlock(&of_fdt_unflatten_mutex);
 449
 450	return mem;
 451}
 452EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 453
 454/* Everything below here references initial_boot_params directly. */
 455int __initdata dt_root_addr_cells;
 456int __initdata dt_root_size_cells;
 457
 458void *initial_boot_params __ro_after_init;
 459phys_addr_t initial_boot_params_pa __ro_after_init;
 460
 461#ifdef CONFIG_OF_EARLY_FLATTREE
 462
 463static u32 of_fdt_crc32;
 464
 465/*
 466 * fdt_reserve_elfcorehdr() - reserves memory for elf core header
 467 *
 468 * This function reserves the memory occupied by an elf core header
 469 * described in the device tree. This region contains all the
 470 * information about primary kernel's core image and is used by a dump
 471 * capture kernel to access the system memory on primary kernel.
 472 */
 473static void __init fdt_reserve_elfcorehdr(void)
 
 474{
 475	if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size)
 476		return;
 
 
 
 477
 478	if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
 479		pr_warn("elfcorehdr is overlapped\n");
 480		return;
 
 
 
 
 
 481	}
 482
 483	memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
 484
 485	pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
 486		elfcorehdr_size >> 10, elfcorehdr_addr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 487}
 488
 489/**
 490 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 491 *
 492 * This function grabs memory from early allocator for device exclusive use
 493 * defined in device tree structures. It should be called by arch specific code
 494 * once the early allocator (i.e. memblock) has been fully activated.
 495 */
 496void __init early_init_fdt_scan_reserved_mem(void)
 497{
 498	int n;
 499	u64 base, size;
 500
 501	if (!initial_boot_params)
 502		return;
 503
 504	fdt_scan_reserved_mem();
 505	fdt_reserve_elfcorehdr();
 506
 507	/* Process header /memreserve/ fields */
 508	for (n = 0; ; n++) {
 509		fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 510		if (!size)
 511			break;
 512		memblock_reserve(base, size);
 513	}
 
 
 
 514}
 515
 516/**
 517 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
 518 */
 519void __init early_init_fdt_reserve_self(void)
 520{
 521	if (!initial_boot_params)
 522		return;
 523
 524	/* Reserve the dtb region */
 525	memblock_reserve(__pa(initial_boot_params),
 526			 fdt_totalsize(initial_boot_params));
 
 527}
 528
 529/**
 530 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 531 * @it: callback function
 532 * @data: context data pointer
 533 *
 534 * This function is used to scan the flattened device-tree, it is
 535 * used to extract the memory information at boot before we can
 536 * unflatten the tree
 537 */
 538int __init of_scan_flat_dt(int (*it)(unsigned long node,
 539				     const char *uname, int depth,
 540				     void *data),
 541			   void *data)
 542{
 543	const void *blob = initial_boot_params;
 544	const char *pathp;
 545	int offset, rc = 0, depth = -1;
 546
 547	if (!blob)
 548		return 0;
 549
 550	for (offset = fdt_next_node(blob, -1, &depth);
 551	     offset >= 0 && depth >= 0 && !rc;
 552	     offset = fdt_next_node(blob, offset, &depth)) {
 553
 554		pathp = fdt_get_name(blob, offset, NULL);
 
 
 555		rc = it(offset, pathp, depth, data);
 556	}
 557	return rc;
 558}
 559
 560/**
 561 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
 562 * @parent: parent node
 563 * @it: callback function
 564 * @data: context data pointer
 565 *
 566 * This function is used to scan sub-nodes of a node.
 567 */
 568int __init of_scan_flat_dt_subnodes(unsigned long parent,
 569				    int (*it)(unsigned long node,
 570					      const char *uname,
 571					      void *data),
 572				    void *data)
 573{
 574	const void *blob = initial_boot_params;
 575	int node;
 576
 577	fdt_for_each_subnode(node, blob, parent) {
 578		const char *pathp;
 579		int rc;
 580
 581		pathp = fdt_get_name(blob, node, NULL);
 582		rc = it(node, pathp, data);
 583		if (rc)
 584			return rc;
 585	}
 586	return 0;
 587}
 588
 589/**
 590 * of_get_flat_dt_subnode_by_name - get the subnode by given name
 591 *
 592 * @node: the parent node
 593 * @uname: the name of subnode
 594 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
 595 */
 596
 597int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
 598{
 599	return fdt_subnode_offset(initial_boot_params, node, uname);
 600}
 601
 602/*
 603 * of_get_flat_dt_root - find the root node in the flat blob
 604 */
 605unsigned long __init of_get_flat_dt_root(void)
 606{
 607	return 0;
 608}
 609
 610/*
 611 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 612 *
 613 * This function can be used within scan_flattened_dt callback to get
 614 * access to properties
 615 */
 616const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 617				       int *size)
 618{
 619	return fdt_getprop(initial_boot_params, node, name, size);
 620}
 621
 622/**
 623 * of_fdt_is_compatible - Return true if given node from the given blob has
 624 * compat in its compatible list
 625 * @blob: A device tree blob
 626 * @node: node to test
 627 * @compat: compatible string to compare with compatible list.
 628 *
 629 * Return: a non-zero value on match with smaller values returned for more
 630 * specific compatible values.
 631 */
 632static int of_fdt_is_compatible(const void *blob,
 633		      unsigned long node, const char *compat)
 634{
 635	const char *cp;
 636	int cplen;
 637	unsigned long l, score = 0;
 638
 639	cp = fdt_getprop(blob, node, "compatible", &cplen);
 640	if (cp == NULL)
 641		return 0;
 642	while (cplen > 0) {
 643		score++;
 644		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 645			return score;
 646		l = strlen(cp) + 1;
 647		cp += l;
 648		cplen -= l;
 649	}
 650
 651	return 0;
 652}
 653
 654/**
 655 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 656 * @node: node to test
 657 * @compat: compatible string to compare with compatible list.
 658 */
 659int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 660{
 661	return of_fdt_is_compatible(initial_boot_params, node, compat);
 662}
 663
 664/*
 665 * of_flat_dt_match - Return true if node matches a list of compatible values
 666 */
 667static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 668{
 669	unsigned int tmp, score = 0;
 670
 671	if (!compat)
 672		return 0;
 673
 674	while (*compat) {
 675		tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
 676		if (tmp && (score == 0 || (tmp < score)))
 677			score = tmp;
 678		compat++;
 679	}
 680
 681	return score;
 682}
 683
 684/*
 685 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
 686 */
 687uint32_t __init of_get_flat_dt_phandle(unsigned long node)
 688{
 689	return fdt_get_phandle(initial_boot_params, node);
 690}
 
 691
 692const char * __init of_flat_dt_get_machine_name(void)
 693{
 694	const char *name;
 695	unsigned long dt_root = of_get_flat_dt_root();
 696
 697	name = of_get_flat_dt_prop(dt_root, "model", NULL);
 698	if (!name)
 699		name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 700	return name;
 701}
 702
 703/**
 704 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 705 *
 706 * @default_match: A machine specific ptr to return in case of no match.
 707 * @get_next_compat: callback function to return next compatible match table.
 708 *
 709 * Iterate through machine match tables to find the best match for the machine
 710 * compatible string in the FDT.
 711 */
 712const void * __init of_flat_dt_match_machine(const void *default_match,
 713		const void * (*get_next_compat)(const char * const**))
 714{
 715	const void *data = NULL;
 716	const void *best_data = default_match;
 717	const char *const *compat;
 718	unsigned long dt_root;
 719	unsigned int best_score = ~1, score = 0;
 720
 721	dt_root = of_get_flat_dt_root();
 722	while ((data = get_next_compat(&compat))) {
 723		score = of_flat_dt_match(dt_root, compat);
 724		if (score > 0 && score < best_score) {
 725			best_data = data;
 726			best_score = score;
 727		}
 728	}
 729	if (!best_data) {
 730		const char *prop;
 731		int size;
 732
 733		pr_err("\n unrecognized device tree list:\n[ ");
 734
 735		prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 736		if (prop) {
 737			while (size > 0) {
 738				printk("'%s' ", prop);
 739				size -= strlen(prop) + 1;
 740				prop += strlen(prop) + 1;
 741			}
 742		}
 743		printk("]\n\n");
 744		return NULL;
 745	}
 746
 747	pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 748
 749	return best_data;
 750}
 751
 
 
 752static void __early_init_dt_declare_initrd(unsigned long start,
 753					   unsigned long end)
 754{
 755	/*
 756	 * __va() is not yet available this early on some platforms. In that
 757	 * case, the platform uses phys_initrd_start/phys_initrd_size instead
 758	 * and does the VA conversion itself.
 759	 */
 760	if (!IS_ENABLED(CONFIG_ARM64) &&
 761	    !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) {
 762		initrd_start = (unsigned long)__va(start);
 763		initrd_end = (unsigned long)__va(end);
 764		initrd_below_start_ok = 1;
 765	}
 766}
 
 767
 768/**
 769 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 770 * @node: reference to node containing initrd location ('chosen')
 771 */
 772static void __init early_init_dt_check_for_initrd(unsigned long node)
 773{
 774	u64 start, end;
 775	int len;
 776	const __be32 *prop;
 777
 778	if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
 779		return;
 780
 781	pr_debug("Looking for initrd properties... ");
 782
 783	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 784	if (!prop)
 785		return;
 786	start = of_read_number(prop, len/4);
 787
 788	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 789	if (!prop)
 790		return;
 791	end = of_read_number(prop, len/4);
 792	if (start > end)
 793		return;
 794
 795	__early_init_dt_declare_initrd(start, end);
 796	phys_initrd_start = start;
 797	phys_initrd_size = end - start;
 798
 799	pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n", start, end);
 
 800}
 801
 802/**
 803 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
 804 * tree
 805 * @node: reference to node containing elfcorehdr location ('chosen')
 806 */
 807static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
 808{
 809	const __be32 *prop;
 810	int len;
 811
 812	if (!IS_ENABLED(CONFIG_CRASH_DUMP))
 813		return;
 814
 815	pr_debug("Looking for elfcorehdr property... ");
 816
 817	prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
 818	if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
 819		return;
 820
 821	elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
 822	elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop);
 823
 824	pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
 825		 elfcorehdr_addr, elfcorehdr_size);
 826}
 827
 828static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
 829
 830/*
 831 * The main usage of linux,usable-memory-range is for crash dump kernel.
 832 * Originally, the number of usable-memory regions is one. Now there may
 833 * be two regions, low region and high region.
 834 * To make compatibility with existing user-space and older kdump, the low
 835 * region is always the last range of linux,usable-memory-range if exist.
 836 */
 837#define MAX_USABLE_RANGES		2
 838
 839/**
 840 * early_init_dt_check_for_usable_mem_range - Decode usable memory range
 841 * location from flat tree
 842 */
 843void __init early_init_dt_check_for_usable_mem_range(void)
 844{
 845	struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
 846	const __be32 *prop, *endp;
 847	int len, i;
 848	unsigned long node = chosen_node_offset;
 849
 850	if ((long)node < 0)
 851		return;
 852
 853	pr_debug("Looking for usable-memory-range property... ");
 854
 855	prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
 856	if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells)))
 857		return;
 858
 859	endp = prop + (len / sizeof(__be32));
 860	for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) {
 861		rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 862		rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop);
 863
 864		pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
 865			 i, &rgn[i].base, &rgn[i].size);
 866	}
 867
 868	memblock_cap_memory_range(rgn[0].base, rgn[0].size);
 869	for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)
 870		memblock_add(rgn[i].base, rgn[i].size);
 871}
 
 872
 873#ifdef CONFIG_SERIAL_EARLYCON
 874
 875int __init early_init_dt_scan_chosen_stdout(void)
 876{
 877	int offset;
 878	const char *p, *q, *options = NULL;
 879	int l;
 880	const struct earlycon_id *match;
 881	const void *fdt = initial_boot_params;
 882	int ret;
 883
 884	offset = fdt_path_offset(fdt, "/chosen");
 885	if (offset < 0)
 886		offset = fdt_path_offset(fdt, "/chosen@0");
 887	if (offset < 0)
 888		return -ENOENT;
 889
 890	p = fdt_getprop(fdt, offset, "stdout-path", &l);
 891	if (!p)
 892		p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 893	if (!p || !l)
 894		return -ENOENT;
 895
 896	q = strchrnul(p, ':');
 897	if (*q != '\0')
 898		options = q + 1;
 899	l = q - p;
 900
 901	/* Get the node specified by stdout-path */
 902	offset = fdt_path_offset_namelen(fdt, p, l);
 903	if (offset < 0) {
 904		pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
 905		return 0;
 906	}
 907
 908	for (match = __earlycon_table; match < __earlycon_table_end; match++) {
 909		if (!match->compatible[0])
 910			continue;
 911
 912		if (fdt_node_check_compatible(fdt, offset, match->compatible))
 913			continue;
 914
 915		ret = of_setup_earlycon(match, offset, options);
 916		if (!ret || ret == -EALREADY)
 917			return 0;
 918	}
 919	return -ENODEV;
 920}
 
 
 
 
 
 
 
 
 
 921#endif
 922
 923/*
 924 * early_init_dt_scan_root - fetch the top level address and size cells
 925 */
 926int __init early_init_dt_scan_root(void)
 
 927{
 928	const __be32 *prop;
 929	const void *fdt = initial_boot_params;
 930	int node = fdt_path_offset(fdt, "/");
 931
 932	if (node < 0)
 933		return -ENODEV;
 934
 935	dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 936	dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 937
 938	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 939	if (!WARN(!prop, "No '#size-cells' in root node\n"))
 940		dt_root_size_cells = be32_to_cpup(prop);
 941	pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 942
 943	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 944	if (!WARN(!prop, "No '#address-cells' in root node\n"))
 945		dt_root_addr_cells = be32_to_cpup(prop);
 946	pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 947
 948	return 0;
 
 949}
 950
 951u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
 952{
 953	const __be32 *p = *cellp;
 954
 955	*cellp = p + s;
 956	return of_read_number(p, s);
 957}
 958
 959/*
 960 * early_init_dt_scan_memory - Look for and parse memory nodes
 961 */
 962int __init early_init_dt_scan_memory(void)
 
 963{
 964	int node, found_memory = 0;
 965	const void *fdt = initial_boot_params;
 966
 967	fdt_for_each_subnode(node, fdt, 0) {
 968		const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 969		const __be32 *reg, *endp;
 970		int l;
 971		bool hotpluggable;
 972
 973		/* We are scanning "memory" nodes only */
 974		if (type == NULL || strcmp(type, "memory") != 0)
 975			continue;
 976
 977		if (!of_fdt_device_is_available(fdt, node))
 978			continue;
 979
 980		reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
 981		if (reg == NULL)
 982			reg = of_get_flat_dt_prop(node, "reg", &l);
 983		if (reg == NULL)
 984			continue;
 985
 986		endp = reg + (l / sizeof(__be32));
 987		hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
 988
 989		pr_debug("memory scan node %s, reg size %d,\n",
 990			 fdt_get_name(fdt, node, NULL), l);
 
 
 
 
 
 
 
 
 991
 992		while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
 993			u64 base, size;
 
 
 
 994
 995			base = dt_mem_next_cell(dt_root_addr_cells, &reg);
 996			size = dt_mem_next_cell(dt_root_size_cells, &reg);
 997
 998			if (size == 0)
 999				continue;
1000			pr_debug(" - %llx, %llx\n", base, size);
1001
1002			early_init_dt_add_memory_arch(base, size);
 
1003
1004			found_memory = 1;
 
1005
1006			if (!hotpluggable)
1007				continue;
 
 
1008
1009			if (memblock_mark_hotplug(base, size))
1010				pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1011					base, base + size);
1012		}
1013	}
1014	return found_memory;
 
1015}
1016
1017int __init early_init_dt_scan_chosen(char *cmdline)
 
1018{
1019	int l, node;
1020	const char *p;
1021	const void *rng_seed;
1022	const void *fdt = initial_boot_params;
1023
1024	node = fdt_path_offset(fdt, "/chosen");
1025	if (node < 0)
1026		node = fdt_path_offset(fdt, "/chosen@0");
1027	if (node < 0)
1028		/* Handle the cmdline config options even if no /chosen node */
1029		goto handle_cmdline;
1030
1031	chosen_node_offset = node;
 
 
1032
1033	early_init_dt_check_for_initrd(node);
1034	early_init_dt_check_for_elfcorehdr(node);
1035
1036	rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1037	if (rng_seed && l > 0) {
1038		add_bootloader_randomness(rng_seed, l);
1039
1040		/* try to clear seed so it won't be found. */
1041		fdt_nop_property(initial_boot_params, node, "rng-seed");
1042
1043		/* update CRC check value */
1044		of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1045				fdt_totalsize(initial_boot_params));
1046	}
1047
1048	/* Retrieve command line */
1049	p = of_get_flat_dt_prop(node, "bootargs", &l);
1050	if (p != NULL && l > 0)
1051		strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
1052
1053handle_cmdline:
1054	/*
1055	 * CONFIG_CMDLINE is meant to be a default in case nothing else
1056	 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1057	 * is set in which case we override whatever was found earlier.
1058	 */
1059#ifdef CONFIG_CMDLINE
1060#if defined(CONFIG_CMDLINE_EXTEND)
1061	strlcat(cmdline, " ", COMMAND_LINE_SIZE);
1062	strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1063#elif defined(CONFIG_CMDLINE_FORCE)
1064	strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1065#else
1066	/* No arguments from boot loader, use kernel's  cmdl*/
1067	if (!((char *)cmdline)[0])
1068		strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1069#endif
 
1070#endif /* CONFIG_CMDLINE */
1071
1072	pr_debug("Command line is: %s\n", (char *)cmdline);
1073
1074	return 0;
 
1075}
1076
 
1077#ifndef MIN_MEMBLOCK_ADDR
1078#define MIN_MEMBLOCK_ADDR	__pa(PAGE_OFFSET)
1079#endif
1080#ifndef MAX_MEMBLOCK_ADDR
1081#define MAX_MEMBLOCK_ADDR	((phys_addr_t)~0)
1082#endif
1083
1084void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1085{
1086	const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1087
1088	if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1089		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1090			base, base + size);
1091		return;
1092	}
1093
1094	if (!PAGE_ALIGNED(base)) {
 
 
 
 
 
1095		size -= PAGE_SIZE - (base & ~PAGE_MASK);
1096		base = PAGE_ALIGN(base);
1097	}
1098	size &= PAGE_MASK;
1099
1100	if (base > MAX_MEMBLOCK_ADDR) {
1101		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1102			base, base + size);
1103		return;
1104	}
1105
1106	if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1107		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1108			((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1109		size = MAX_MEMBLOCK_ADDR - base + 1;
1110	}
1111
1112	if (base + size < phys_offset) {
1113		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1114			base, base + size);
1115		return;
1116	}
1117	if (base < phys_offset) {
1118		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1119			base, phys_offset);
1120		size -= phys_offset - base;
1121		base = phys_offset;
1122	}
1123	memblock_add(base, size);
1124}
1125
1126static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1127{
1128	void *ptr = memblock_alloc(size, align);
 
1129
1130	if (!ptr)
1131		panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1132		      __func__, size, align);
 
 
 
 
1133
1134	return ptr;
 
 
 
1135}
 
1136
1137bool __init early_init_dt_verify(void *dt_virt, phys_addr_t dt_phys)
1138{
1139	if (!dt_virt)
1140		return false;
1141
1142	/* check device tree validity */
1143	if (fdt_check_header(dt_virt))
1144		return false;
1145
1146	/* Setup flat device-tree pointer */
1147	initial_boot_params = dt_virt;
1148	initial_boot_params_pa = dt_phys;
1149	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1150				fdt_totalsize(initial_boot_params));
1151
1152	/* Initialize {size,address}-cells info */
1153	early_init_dt_scan_root();
1154
1155	return true;
1156}
1157
1158
1159void __init early_init_dt_scan_nodes(void)
1160{
1161	int rc;
1162
1163	/* Retrieve various information from the /chosen node */
1164	rc = early_init_dt_scan_chosen(boot_command_line);
1165	if (rc)
1166		pr_warn("No chosen node found, continuing without\n");
1167
1168	/* Setup memory, calling early_init_dt_add_memory_arch */
1169	early_init_dt_scan_memory();
1170
1171	/* Handle linux,usable-memory-range property */
1172	early_init_dt_check_for_usable_mem_range();
1173}
1174
1175bool __init early_init_dt_scan(void *dt_virt, phys_addr_t dt_phys)
1176{
1177	bool status;
1178
1179	status = early_init_dt_verify(dt_virt, dt_phys);
1180	if (!status)
1181		return false;
1182
1183	early_init_dt_scan_nodes();
1184	return true;
1185}
1186
1187static void *__init copy_device_tree(void *fdt)
1188{
1189	int size;
1190	void *dt;
1191
1192	size = fdt_totalsize(fdt);
1193	dt = early_init_dt_alloc_memory_arch(size,
1194					     roundup_pow_of_two(FDT_V17_SIZE));
1195
1196	if (dt)
1197		memcpy(dt, fdt, size);
1198
1199	return dt;
1200}
1201
1202/**
1203 * unflatten_device_tree - create tree of device_nodes from flat blob
1204 *
1205 * unflattens the device-tree passed by the firmware, creating the
1206 * tree of struct device_node. It also fills the "name" and "type"
1207 * pointers of the nodes so the normal device-tree walking functions
1208 * can be used.
1209 */
1210void __init unflatten_device_tree(void)
1211{
1212	void *fdt = initial_boot_params;
1213
1214	/* Save the statically-placed regions in the reserved_mem array */
1215	fdt_scan_reserved_mem_reg_nodes();
1216
1217	/* Populate an empty root node when bootloader doesn't provide one */
1218	if (!fdt) {
1219		fdt = (void *) __dtb_empty_root_begin;
1220		/* fdt_totalsize() will be used for copy size */
1221		if (fdt_totalsize(fdt) >
1222		    __dtb_empty_root_end - __dtb_empty_root_begin) {
1223			pr_err("invalid size in dtb_empty_root\n");
1224			return;
1225		}
1226		of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt));
1227		fdt = copy_device_tree(fdt);
1228	}
1229
1230	__unflatten_device_tree(fdt, NULL, &of_root,
1231				early_init_dt_alloc_memory_arch, false);
1232
1233	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1234	of_alias_scan(early_init_dt_alloc_memory_arch);
1235
1236	unittest_unflatten_overlay_base();
1237}
1238
1239/**
1240 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1241 *
1242 * Copies and unflattens the device-tree passed by the firmware, creating the
1243 * tree of struct device_node. It also fills the "name" and "type"
1244 * pointers of the nodes so the normal device-tree walking functions
1245 * can be used. This should only be used when the FDT memory has not been
1246 * reserved such is the case when the FDT is built-in to the kernel init
1247 * section. If the FDT memory is reserved already then unflatten_device_tree
1248 * should be used instead.
1249 */
1250void __init unflatten_and_copy_device_tree(void)
1251{
1252	if (initial_boot_params)
1253		initial_boot_params = copy_device_tree(initial_boot_params);
1254
 
 
 
 
 
 
 
 
 
 
 
 
 
1255	unflatten_device_tree();
1256}
1257
1258#ifdef CONFIG_SYSFS
1259static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1260			       struct bin_attribute *bin_attr,
1261			       char *buf, loff_t off, size_t count)
1262{
1263	memcpy(buf, initial_boot_params + off, count);
1264	return count;
1265}
1266
1267static int __init of_fdt_raw_init(void)
1268{
1269	static struct bin_attribute of_fdt_raw_attr =
1270		__BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1271
1272	if (!initial_boot_params)
1273		return 0;
1274
1275	if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1276				     fdt_totalsize(initial_boot_params))) {
1277		pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1278		return 0;
1279	}
1280	of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1281	return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1282}
1283late_initcall(of_fdt_raw_init);
1284#endif
1285
1286#endif /* CONFIG_OF_EARLY_FLATTREE */
v4.6
 
   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#include <linux/crc32.h>
  13#include <linux/kernel.h>
  14#include <linux/initrd.h>
  15#include <linux/memblock.h>
  16#include <linux/mutex.h>
  17#include <linux/of.h>
  18#include <linux/of_fdt.h>
  19#include <linux/of_reserved_mem.h>
  20#include <linux/sizes.h>
  21#include <linux/string.h>
  22#include <linux/errno.h>
  23#include <linux/slab.h>
  24#include <linux/libfdt.h>
  25#include <linux/debugfs.h>
  26#include <linux/serial_core.h>
  27#include <linux/sysfs.h>
 
  28
  29#include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  30#include <asm/page.h>
  31
 
 
 
 
 
 
 
 
 
  32/*
  33 * of_fdt_limit_memory - limit the number of regions in the /memory node
  34 * @limit: maximum entries
  35 *
  36 * Adjust the flattened device tree to have at most 'limit' number of
  37 * memory entries in the /memory node. This function may be called
  38 * any time after initial_boot_param is set.
  39 */
  40void of_fdt_limit_memory(int limit)
  41{
  42	int memory;
  43	int len;
  44	const void *val;
  45	int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
  46	int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
  47	const uint32_t *addr_prop;
  48	const uint32_t *size_prop;
  49	int root_offset;
  50	int cell_size;
  51
  52	root_offset = fdt_path_offset(initial_boot_params, "/");
  53	if (root_offset < 0)
  54		return;
  55
  56	addr_prop = fdt_getprop(initial_boot_params, root_offset,
  57				"#address-cells", NULL);
  58	if (addr_prop)
  59		nr_address_cells = fdt32_to_cpu(*addr_prop);
  60
  61	size_prop = fdt_getprop(initial_boot_params, root_offset,
  62				"#size-cells", NULL);
  63	if (size_prop)
  64		nr_size_cells = fdt32_to_cpu(*size_prop);
  65
  66	cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
  67
  68	memory = fdt_path_offset(initial_boot_params, "/memory");
  69	if (memory > 0) {
  70		val = fdt_getprop(initial_boot_params, memory, "reg", &len);
  71		if (len > limit*cell_size) {
  72			len = limit*cell_size;
  73			pr_debug("Limiting number of entries to %d\n", limit);
  74			fdt_setprop(initial_boot_params, memory, "reg", val,
  75					len);
  76		}
  77	}
  78}
  79
  80/**
  81 * of_fdt_is_compatible - Return true if given node from the given blob has
  82 * compat in its compatible list
  83 * @blob: A device tree blob
  84 * @node: node to test
  85 * @compat: compatible string to compare with compatible list.
  86 *
  87 * On match, returns a non-zero value with smaller values returned for more
  88 * specific compatible values.
  89 */
  90int of_fdt_is_compatible(const void *blob,
  91		      unsigned long node, const char *compat)
  92{
  93	const char *cp;
  94	int cplen;
  95	unsigned long l, score = 0;
  96
  97	cp = fdt_getprop(blob, node, "compatible", &cplen);
  98	if (cp == NULL)
  99		return 0;
 100	while (cplen > 0) {
 101		score++;
 102		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
 103			return score;
 104		l = strlen(cp) + 1;
 105		cp += l;
 106		cplen -= l;
 107	}
 108
 109	return 0;
 110}
 111
 112/**
 113 * of_fdt_is_big_endian - Return true if given node needs BE MMIO accesses
 114 * @blob: A device tree blob
 115 * @node: node to test
 116 *
 117 * Returns true if the node has a "big-endian" property, or if the kernel
 118 * was compiled for BE *and* the node has a "native-endian" property.
 119 * Returns false otherwise.
 120 */
 121bool of_fdt_is_big_endian(const void *blob, unsigned long node)
 122{
 123	if (fdt_getprop(blob, node, "big-endian", NULL))
 124		return true;
 125	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
 126	    fdt_getprop(blob, node, "native-endian", NULL))
 127		return true;
 128	return false;
 129}
 130
 131/**
 132 * of_fdt_match - Return true if node matches a list of compatible values
 133 */
 134int of_fdt_match(const void *blob, unsigned long node,
 135                 const char *const *compat)
 136{
 137	unsigned int tmp, score = 0;
 138
 139	if (!compat)
 140		return 0;
 141
 142	while (*compat) {
 143		tmp = of_fdt_is_compatible(blob, node, *compat);
 144		if (tmp && (score == 0 || (tmp < score)))
 145			score = tmp;
 146		compat++;
 147	}
 148
 149	return score;
 150}
 151
 152static void *unflatten_dt_alloc(void **mem, unsigned long size,
 153				       unsigned long align)
 154{
 155	void *res;
 156
 157	*mem = PTR_ALIGN(*mem, align);
 158	res = *mem;
 159	*mem += size;
 160
 161	return res;
 162}
 163
 164/**
 165 * unflatten_dt_node - Alloc and populate a device_node from the flat tree
 166 * @blob: The parent device tree blob
 167 * @mem: Memory chunk to use for allocating device nodes and properties
 168 * @poffset: pointer to node in flat tree
 169 * @dad: Parent struct device_node
 170 * @nodepp: The device_node tree created by the call
 171 * @fpsize: Size of the node path up at the current depth.
 172 * @dryrun: If true, do not allocate device nodes but still calculate needed
 173 * memory size
 174 */
 175static void * unflatten_dt_node(const void *blob,
 176				void *mem,
 177				int *poffset,
 178				struct device_node *dad,
 179				struct device_node **nodepp,
 180				unsigned long fpsize,
 181				bool dryrun)
 182{
 183	const __be32 *p;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 184	struct device_node *np;
 185	struct property *pp, **prev_pp = NULL;
 186	const char *pathp;
 187	unsigned int l, allocl;
 188	static int depth;
 189	int old_depth;
 190	int offset;
 191	int has_name = 0;
 192	int new_format = 0;
 193
 194	pathp = fdt_get_name(blob, *poffset, &l);
 195	if (!pathp)
 196		return mem;
 197
 198	allocl = ++l;
 199
 200	/* version 0x10 has a more compact unit name here instead of the full
 201	 * path. we accumulate the full path size using "fpsize", we'll rebuild
 202	 * it later. We detect this because the first character of the name is
 203	 * not '/'.
 204	 */
 205	if ((*pathp) != '/') {
 206		new_format = 1;
 207		if (fpsize == 0) {
 208			/* root node: special case. fpsize accounts for path
 209			 * plus terminating zero. root node only has '/', so
 210			 * fpsize should be 2, but we want to avoid the first
 211			 * level nodes to have two '/' so we use fpsize 1 here
 212			 */
 213			fpsize = 1;
 214			allocl = 2;
 215			l = 1;
 216			pathp = "";
 217		} else {
 218			/* account for '/' and path size minus terminal 0
 219			 * already in 'l'
 220			 */
 221			fpsize += l;
 222			allocl = fpsize;
 223		}
 224	}
 225
 226	np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
 
 
 227				__alignof__(struct device_node));
 228	if (!dryrun) {
 229		char *fn;
 230		of_node_init(np);
 231		np->full_name = fn = ((char *)np) + sizeof(*np);
 232		if (new_format) {
 233			/* rebuild full path for new format */
 234			if (dad && dad->parent) {
 235				strcpy(fn, dad->full_name);
 236#ifdef DEBUG
 237				if ((strlen(fn) + l + 1) != allocl) {
 238					pr_debug("%s: p: %d, l: %d, a: %d\n",
 239						pathp, (int)strlen(fn),
 240						l, allocl);
 241				}
 242#endif
 243				fn += strlen(fn);
 244			}
 245			*(fn++) = '/';
 246		}
 247		memcpy(fn, pathp, l);
 248
 249		prev_pp = &np->properties;
 
 250		if (dad != NULL) {
 251			np->parent = dad;
 252			np->sibling = dad->child;
 253			dad->child = np;
 254		}
 255	}
 256	/* process properties */
 257	for (offset = fdt_first_property_offset(blob, *poffset);
 258	     (offset >= 0);
 259	     (offset = fdt_next_property_offset(blob, offset))) {
 260		const char *pname;
 261		u32 sz;
 262
 263		if (!(p = fdt_getprop_by_offset(blob, offset, &pname, &sz))) {
 264			offset = -FDT_ERR_INTERNAL;
 265			break;
 266		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 267
 268		if (pname == NULL) {
 269			pr_info("Can't find property name in list !\n");
 270			break;
 271		}
 272		if (strcmp(pname, "name") == 0)
 273			has_name = 1;
 274		pp = unflatten_dt_alloc(&mem, sizeof(struct property),
 275					__alignof__(struct property));
 276		if (!dryrun) {
 277			/* We accept flattened tree phandles either in
 278			 * ePAPR-style "phandle" properties, or the
 279			 * legacy "linux,phandle" properties.  If both
 280			 * appear and have different values, things
 281			 * will get weird.  Don't do that. */
 282			if ((strcmp(pname, "phandle") == 0) ||
 283			    (strcmp(pname, "linux,phandle") == 0)) {
 284				if (np->phandle == 0)
 285					np->phandle = be32_to_cpup(p);
 286			}
 287			/* And we process the "ibm,phandle" property
 288			 * used in pSeries dynamic device tree
 289			 * stuff */
 290			if (strcmp(pname, "ibm,phandle") == 0)
 291				np->phandle = be32_to_cpup(p);
 292			pp->name = (char *)pname;
 293			pp->length = sz;
 294			pp->value = (__be32 *)p;
 295			*prev_pp = pp;
 296			prev_pp = &pp->next;
 297		}
 298	}
 299	/* with version 0x10 we may not have the name property, recreate
 300	 * it here from the unit name if absent
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 301	 */
 302	if (!has_name) {
 303		const char *p1 = pathp, *ps = pathp, *pa = NULL;
 304		int sz;
 
 
 
 
 
 
 
 
 
 
 
 
 305
 306		while (*p1) {
 307			if ((*p1) == '@')
 308				pa = p1;
 309			if ((*p1) == '/')
 310				ps = p1 + 1;
 311			p1++;
 312		}
 313		if (pa < ps)
 314			pa = p1;
 315		sz = (pa - ps) + 1;
 316		pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
 317					__alignof__(struct property));
 318		if (!dryrun) {
 319			pp->name = "name";
 320			pp->length = sz;
 321			pp->value = pp + 1;
 322			*prev_pp = pp;
 323			prev_pp = &pp->next;
 324			memcpy(pp->value, ps, sz - 1);
 325			((char *)pp->value)[sz - 1] = 0;
 326			pr_debug("fixed up name for %s -> %s\n", pathp,
 327				(char *)pp->value);
 328		}
 329	}
 330	if (!dryrun) {
 331		*prev_pp = NULL;
 332		np->name = of_get_property(np, "name", NULL);
 333		np->type = of_get_property(np, "device_type", NULL);
 334
 335		if (!np->name)
 336			np->name = "<NULL>";
 337		if (!np->type)
 338			np->type = "<NULL>";
 339	}
 340
 341	old_depth = depth;
 342	*poffset = fdt_next_node(blob, *poffset, &depth);
 343	if (depth < 0)
 344		depth = 0;
 345	while (*poffset > 0 && depth > old_depth)
 346		mem = unflatten_dt_node(blob, mem, poffset, np, NULL,
 347					fpsize, dryrun);
 348
 349	if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND)
 350		pr_err("unflatten: error %d processing FDT\n", *poffset);
 351
 352	/*
 353	 * Reverse the child list. Some drivers assumes node order matches .dts
 354	 * node order
 355	 */
 356	if (!dryrun && np->child) {
 357		struct device_node *child = np->child;
 358		np->child = NULL;
 359		while (child) {
 360			struct device_node *next = child->sibling;
 361			child->sibling = np->child;
 362			np->child = child;
 363			child = next;
 364		}
 365	}
 366
 367	if (nodepp)
 368		*nodepp = np;
 369
 370	return mem;
 371}
 372
 373/**
 374 * __unflatten_device_tree - create tree of device_nodes from flat blob
 375 *
 376 * unflattens a device-tree, creating the
 377 * tree of struct device_node. It also fills the "name" and "type"
 378 * pointers of the nodes so the normal device-tree walking functions
 379 * can be used.
 380 * @blob: The blob to expand
 
 381 * @mynodes: The device_node tree created by the call
 382 * @dt_alloc: An allocator that provides a virtual address to memory
 383 * for the resulting tree
 
 
 
 
 
 
 
 
 384 */
 385static void __unflatten_device_tree(const void *blob,
 386			     struct device_node **mynodes,
 387			     void * (*dt_alloc)(u64 size, u64 align))
 
 
 388{
 389	unsigned long size;
 390	int start;
 391	void *mem;
 
 
 
 
 392
 393	pr_debug(" -> unflatten_device_tree()\n");
 394
 395	if (!blob) {
 396		pr_debug("No device tree pointer\n");
 397		return;
 398	}
 399
 400	pr_debug("Unflattening device tree:\n");
 401	pr_debug("magic: %08x\n", fdt_magic(blob));
 402	pr_debug("size: %08x\n", fdt_totalsize(blob));
 403	pr_debug("version: %08x\n", fdt_version(blob));
 404
 405	if (fdt_check_header(blob)) {
 406		pr_err("Invalid device tree blob header\n");
 407		return;
 408	}
 409
 410	/* First pass, scan for size */
 411	start = 0;
 412	size = (unsigned long)unflatten_dt_node(blob, NULL, &start, NULL, NULL, 0, true);
 
 
 413	size = ALIGN(size, 4);
 414
 415	pr_debug("  size is %lx, allocating...\n", size);
 416
 417	/* Allocate memory for the expanded device tree */
 418	mem = dt_alloc(size + 4, __alignof__(struct device_node));
 
 
 
 419	memset(mem, 0, size);
 420
 421	*(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 422
 423	pr_debug("  unflattening %p...\n", mem);
 424
 425	/* Second pass, do actual unflattening */
 426	start = 0;
 427	unflatten_dt_node(blob, mem, &start, NULL, mynodes, 0, false);
 428	if (be32_to_cpup(mem + size) != 0xdeadbeef)
 429		pr_warning("End of tree marker overwritten: %08x\n",
 430			   be32_to_cpup(mem + size));
 
 
 
 
 
 
 
 
 431
 432	pr_debug(" <- unflatten_device_tree()\n");
 
 433}
 434
 435static void *kernel_tree_alloc(u64 size, u64 align)
 436{
 437	return kzalloc(size, GFP_KERNEL);
 438}
 439
 440static DEFINE_MUTEX(of_fdt_unflatten_mutex);
 441
 442/**
 443 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 
 
 
 444 *
 445 * unflattens the device-tree passed by the firmware, creating the
 446 * tree of struct device_node. It also fills the "name" and "type"
 447 * pointers of the nodes so the normal device-tree walking functions
 448 * can be used.
 
 
 
 449 */
 450void of_fdt_unflatten_tree(const unsigned long *blob,
 451			struct device_node **mynodes)
 
 452{
 
 
 453	mutex_lock(&of_fdt_unflatten_mutex);
 454	__unflatten_device_tree(blob, mynodes, &kernel_tree_alloc);
 
 455	mutex_unlock(&of_fdt_unflatten_mutex);
 
 
 456}
 457EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 458
 459/* Everything below here references initial_boot_params directly. */
 460int __initdata dt_root_addr_cells;
 461int __initdata dt_root_size_cells;
 462
 463void *initial_boot_params;
 
 464
 465#ifdef CONFIG_OF_EARLY_FLATTREE
 466
 467static u32 of_fdt_crc32;
 468
 469/**
 470 * res_mem_reserve_reg() - reserve all memory described in 'reg' property
 
 
 
 
 
 471 */
 472static int __init __reserved_mem_reserve_reg(unsigned long node,
 473					     const char *uname)
 474{
 475	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 476	phys_addr_t base, size;
 477	int len;
 478	const __be32 *prop;
 479	int nomap, first = 1;
 480
 481	prop = of_get_flat_dt_prop(node, "reg", &len);
 482	if (!prop)
 483		return -ENOENT;
 484
 485	if (len && len % t_len != 0) {
 486		pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 487		       uname);
 488		return -EINVAL;
 489	}
 490
 491	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 492
 493	while (len >= t_len) {
 494		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 495		size = dt_mem_next_cell(dt_root_size_cells, &prop);
 496
 497		if (size &&
 498		    early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 499			pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 500				uname, &base, (unsigned long)size / SZ_1M);
 501		else
 502			pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 503				uname, &base, (unsigned long)size / SZ_1M);
 504
 505		len -= t_len;
 506		if (first) {
 507			fdt_reserved_mem_save_node(node, uname, base, size);
 508			first = 0;
 509		}
 510	}
 511	return 0;
 512}
 513
 514/**
 515 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 516 * in /reserved-memory matches the values supported by the current implementation,
 517 * also check if ranges property has been provided
 518 */
 519static int __init __reserved_mem_check_root(unsigned long node)
 520{
 521	const __be32 *prop;
 522
 523	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 524	if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 525		return -EINVAL;
 526
 527	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 528	if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 529		return -EINVAL;
 530
 531	prop = of_get_flat_dt_prop(node, "ranges", NULL);
 532	if (!prop)
 533		return -EINVAL;
 534	return 0;
 535}
 536
 537/**
 538 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 539 */
 540static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 541					  int depth, void *data)
 542{
 543	static int found;
 544	const char *status;
 545	int err;
 546
 547	if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 548		if (__reserved_mem_check_root(node) != 0) {
 549			pr_err("Reserved memory: unsupported node format, ignoring\n");
 550			/* break scan */
 551			return 1;
 552		}
 553		found = 1;
 554		/* scan next node */
 555		return 0;
 556	} else if (!found) {
 557		/* scan next node */
 558		return 0;
 559	} else if (found && depth < 2) {
 560		/* scanning of /reserved-memory has been finished */
 561		return 1;
 562	}
 563
 564	status = of_get_flat_dt_prop(node, "status", NULL);
 565	if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
 566		return 0;
 567
 568	err = __reserved_mem_reserve_reg(node, uname);
 569	if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 570		fdt_reserved_mem_save_node(node, uname, 0, 0);
 571
 572	/* scan next node */
 573	return 0;
 574}
 575
 576/**
 577 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 578 *
 579 * This function grabs memory from early allocator for device exclusive use
 580 * defined in device tree structures. It should be called by arch specific code
 581 * once the early allocator (i.e. memblock) has been fully activated.
 582 */
 583void __init early_init_fdt_scan_reserved_mem(void)
 584{
 585	int n;
 586	u64 base, size;
 587
 588	if (!initial_boot_params)
 589		return;
 590
 
 
 
 591	/* Process header /memreserve/ fields */
 592	for (n = 0; ; n++) {
 593		fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 594		if (!size)
 595			break;
 596		early_init_dt_reserve_memory_arch(base, size, 0);
 597	}
 598
 599	of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 600	fdt_init_reserved_mem();
 601}
 602
 603/**
 604 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
 605 */
 606void __init early_init_fdt_reserve_self(void)
 607{
 608	if (!initial_boot_params)
 609		return;
 610
 611	/* Reserve the dtb region */
 612	early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
 613					  fdt_totalsize(initial_boot_params),
 614					  0);
 615}
 616
 617/**
 618 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 619 * @it: callback function
 620 * @data: context data pointer
 621 *
 622 * This function is used to scan the flattened device-tree, it is
 623 * used to extract the memory information at boot before we can
 624 * unflatten the tree
 625 */
 626int __init of_scan_flat_dt(int (*it)(unsigned long node,
 627				     const char *uname, int depth,
 628				     void *data),
 629			   void *data)
 630{
 631	const void *blob = initial_boot_params;
 632	const char *pathp;
 633	int offset, rc = 0, depth = -1;
 634
 635        for (offset = fdt_next_node(blob, -1, &depth);
 636             offset >= 0 && depth >= 0 && !rc;
 637             offset = fdt_next_node(blob, offset, &depth)) {
 
 
 
 638
 639		pathp = fdt_get_name(blob, offset, NULL);
 640		if (*pathp == '/')
 641			pathp = kbasename(pathp);
 642		rc = it(offset, pathp, depth, data);
 643	}
 644	return rc;
 645}
 646
 647/**
 648 * of_get_flat_dt_root - find the root node in the flat blob
 
 
 
 
 
 649 */
 650unsigned long __init of_get_flat_dt_root(void)
 
 
 
 
 651{
 
 
 
 
 
 
 
 
 
 
 
 
 652	return 0;
 653}
 654
 655/**
 656 * of_get_flat_dt_size - Return the total size of the FDT
 
 
 
 
 
 
 
 
 
 
 
 
 
 657 */
 658int __init of_get_flat_dt_size(void)
 659{
 660	return fdt_totalsize(initial_boot_params);
 661}
 662
 663/**
 664 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 665 *
 666 * This function can be used within scan_flattened_dt callback to get
 667 * access to properties
 668 */
 669const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 670				       int *size)
 671{
 672	return fdt_getprop(initial_boot_params, node, name, size);
 673}
 674
 675/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 676 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 677 * @node: node to test
 678 * @compat: compatible string to compare with compatible list.
 679 */
 680int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 681{
 682	return of_fdt_is_compatible(initial_boot_params, node, compat);
 683}
 684
 685/**
 686 * of_flat_dt_match - Return true if node matches a list of compatible values
 687 */
 688int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 689{
 690	return of_fdt_match(initial_boot_params, node, compat);
 
 
 
 
 
 
 
 
 
 
 
 
 691}
 692
 693struct fdt_scan_status {
 694	const char *name;
 695	int namelen;
 696	int depth;
 697	int found;
 698	int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 699	void *data;
 700};
 701
 702const char * __init of_flat_dt_get_machine_name(void)
 703{
 704	const char *name;
 705	unsigned long dt_root = of_get_flat_dt_root();
 706
 707	name = of_get_flat_dt_prop(dt_root, "model", NULL);
 708	if (!name)
 709		name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 710	return name;
 711}
 712
 713/**
 714 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 715 *
 716 * @default_match: A machine specific ptr to return in case of no match.
 717 * @get_next_compat: callback function to return next compatible match table.
 718 *
 719 * Iterate through machine match tables to find the best match for the machine
 720 * compatible string in the FDT.
 721 */
 722const void * __init of_flat_dt_match_machine(const void *default_match,
 723		const void * (*get_next_compat)(const char * const**))
 724{
 725	const void *data = NULL;
 726	const void *best_data = default_match;
 727	const char *const *compat;
 728	unsigned long dt_root;
 729	unsigned int best_score = ~1, score = 0;
 730
 731	dt_root = of_get_flat_dt_root();
 732	while ((data = get_next_compat(&compat))) {
 733		score = of_flat_dt_match(dt_root, compat);
 734		if (score > 0 && score < best_score) {
 735			best_data = data;
 736			best_score = score;
 737		}
 738	}
 739	if (!best_data) {
 740		const char *prop;
 741		int size;
 742
 743		pr_err("\n unrecognized device tree list:\n[ ");
 744
 745		prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 746		if (prop) {
 747			while (size > 0) {
 748				printk("'%s' ", prop);
 749				size -= strlen(prop) + 1;
 750				prop += strlen(prop) + 1;
 751			}
 752		}
 753		printk("]\n\n");
 754		return NULL;
 755	}
 756
 757	pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 758
 759	return best_data;
 760}
 761
 762#ifdef CONFIG_BLK_DEV_INITRD
 763#ifndef __early_init_dt_declare_initrd
 764static void __early_init_dt_declare_initrd(unsigned long start,
 765					   unsigned long end)
 766{
 767	initrd_start = (unsigned long)__va(start);
 768	initrd_end = (unsigned long)__va(end);
 769	initrd_below_start_ok = 1;
 
 
 
 
 
 
 
 
 770}
 771#endif
 772
 773/**
 774 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 775 * @node: reference to node containing initrd location ('chosen')
 776 */
 777static void __init early_init_dt_check_for_initrd(unsigned long node)
 778{
 779	u64 start, end;
 780	int len;
 781	const __be32 *prop;
 782
 
 
 
 783	pr_debug("Looking for initrd properties... ");
 784
 785	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 786	if (!prop)
 787		return;
 788	start = of_read_number(prop, len/4);
 789
 790	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 791	if (!prop)
 792		return;
 793	end = of_read_number(prop, len/4);
 
 
 794
 795	__early_init_dt_declare_initrd(start, end);
 
 
 796
 797	pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 798		 (unsigned long long)start, (unsigned long long)end);
 799}
 800#else
 801static inline void early_init_dt_check_for_initrd(unsigned long node)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 802{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 803}
 804#endif /* CONFIG_BLK_DEV_INITRD */
 805
 806#ifdef CONFIG_SERIAL_EARLYCON
 807
 808static int __init early_init_dt_scan_chosen_serial(void)
 809{
 810	int offset;
 811	const char *p, *q, *options = NULL;
 812	int l;
 813	const struct earlycon_id *match;
 814	const void *fdt = initial_boot_params;
 
 815
 816	offset = fdt_path_offset(fdt, "/chosen");
 817	if (offset < 0)
 818		offset = fdt_path_offset(fdt, "/chosen@0");
 819	if (offset < 0)
 820		return -ENOENT;
 821
 822	p = fdt_getprop(fdt, offset, "stdout-path", &l);
 823	if (!p)
 824		p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 825	if (!p || !l)
 826		return -ENOENT;
 827
 828	q = strchrnul(p, ':');
 829	if (*q != '\0')
 830		options = q + 1;
 831	l = q - p;
 832
 833	/* Get the node specified by stdout-path */
 834	offset = fdt_path_offset_namelen(fdt, p, l);
 835	if (offset < 0) {
 836		pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
 837		return 0;
 838	}
 839
 840	for (match = __earlycon_table; match < __earlycon_table_end; match++) {
 841		if (!match->compatible[0])
 842			continue;
 843
 844		if (fdt_node_check_compatible(fdt, offset, match->compatible))
 845			continue;
 846
 847		of_setup_earlycon(match, offset, options);
 848		return 0;
 
 849	}
 850	return -ENODEV;
 851}
 852
 853static int __init setup_of_earlycon(char *buf)
 854{
 855	if (buf)
 856		return 0;
 857
 858	return early_init_dt_scan_chosen_serial();
 859}
 860early_param("earlycon", setup_of_earlycon);
 861#endif
 862
 863/**
 864 * early_init_dt_scan_root - fetch the top level address and size cells
 865 */
 866int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 867				   int depth, void *data)
 868{
 869	const __be32 *prop;
 
 
 870
 871	if (depth != 0)
 872		return 0;
 873
 874	dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 875	dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 876
 877	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 878	if (prop)
 879		dt_root_size_cells = be32_to_cpup(prop);
 880	pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 881
 882	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 883	if (prop)
 884		dt_root_addr_cells = be32_to_cpup(prop);
 885	pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 886
 887	/* break now */
 888	return 1;
 889}
 890
 891u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
 892{
 893	const __be32 *p = *cellp;
 894
 895	*cellp = p + s;
 896	return of_read_number(p, s);
 897}
 898
 899/**
 900 * early_init_dt_scan_memory - Look for an parse memory nodes
 901 */
 902int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 903				     int depth, void *data)
 904{
 905	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 906	const __be32 *reg, *endp;
 907	int l;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 908
 909	/* We are scanning "memory" nodes only */
 910	if (type == NULL) {
 911		/*
 912		 * The longtrail doesn't have a device_type on the
 913		 * /memory node, so look for the node called /memory@0.
 914		 */
 915		if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0)
 916			return 0;
 917	} else if (strcmp(type, "memory") != 0)
 918		return 0;
 919
 920	reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
 921	if (reg == NULL)
 922		reg = of_get_flat_dt_prop(node, "reg", &l);
 923	if (reg == NULL)
 924		return 0;
 925
 926	endp = reg + (l / sizeof(__be32));
 
 927
 928	pr_debug("memory scan node %s, reg size %d,\n", uname, l);
 
 
 929
 930	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
 931		u64 base, size;
 932
 933		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
 934		size = dt_mem_next_cell(dt_root_size_cells, &reg);
 935
 936		if (size == 0)
 937			continue;
 938		pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
 939		    (unsigned long long)size);
 940
 941		early_init_dt_add_memory_arch(base, size);
 
 
 
 942	}
 943
 944	return 0;
 945}
 946
 947int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
 948				     int depth, void *data)
 949{
 950	int l;
 951	const char *p;
 
 
 952
 953	pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
 
 
 
 
 
 954
 955	if (depth != 1 || !data ||
 956	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
 957		return 0;
 958
 959	early_init_dt_check_for_initrd(node);
 
 
 
 
 
 
 
 
 
 
 
 
 
 960
 961	/* Retrieve command line */
 962	p = of_get_flat_dt_prop(node, "bootargs", &l);
 963	if (p != NULL && l > 0)
 964		strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
 965
 
 966	/*
 967	 * CONFIG_CMDLINE is meant to be a default in case nothing else
 968	 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
 969	 * is set in which case we override whatever was found earlier.
 970	 */
 971#ifdef CONFIG_CMDLINE
 972#ifndef CONFIG_CMDLINE_FORCE
 973	if (!((char *)data)[0])
 
 
 
 
 
 
 
 974#endif
 975		strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 976#endif /* CONFIG_CMDLINE */
 977
 978	pr_debug("Command line is: %s\n", (char*)data);
 979
 980	/* break now */
 981	return 1;
 982}
 983
 984#ifdef CONFIG_HAVE_MEMBLOCK
 985#ifndef MIN_MEMBLOCK_ADDR
 986#define MIN_MEMBLOCK_ADDR	__pa(PAGE_OFFSET)
 987#endif
 988#ifndef MAX_MEMBLOCK_ADDR
 989#define MAX_MEMBLOCK_ADDR	((phys_addr_t)~0)
 990#endif
 991
 992void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
 993{
 994	const u64 phys_offset = MIN_MEMBLOCK_ADDR;
 995
 
 
 
 
 
 
 996	if (!PAGE_ALIGNED(base)) {
 997		if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
 998			pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
 999				base, base + size);
1000			return;
1001		}
1002		size -= PAGE_SIZE - (base & ~PAGE_MASK);
1003		base = PAGE_ALIGN(base);
1004	}
1005	size &= PAGE_MASK;
1006
1007	if (base > MAX_MEMBLOCK_ADDR) {
1008		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1009				base, base + size);
1010		return;
1011	}
1012
1013	if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1014		pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1015				((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1016		size = MAX_MEMBLOCK_ADDR - base + 1;
1017	}
1018
1019	if (base + size < phys_offset) {
1020		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1021			   base, base + size);
1022		return;
1023	}
1024	if (base < phys_offset) {
1025		pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1026			   base, phys_offset);
1027		size -= phys_offset - base;
1028		base = phys_offset;
1029	}
1030	memblock_add(base, size);
1031}
1032
1033int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1034					phys_addr_t size, bool nomap)
1035{
1036	if (nomap)
1037		return memblock_remove(base, size);
1038	return memblock_reserve(base, size);
1039}
1040
1041/*
1042 * called from unflatten_device_tree() to bootstrap devicetree itself
1043 * Architectures can override this definition if memblock isn't used
1044 */
1045void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
1046{
1047	return __va(memblock_alloc(size, align));
1048}
1049#else
1050void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1051{
1052	WARN_ON(1);
1053}
1054
1055int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1056					phys_addr_t size, bool nomap)
1057{
1058	pr_err("Reserved memory not supported, ignoring range %pa - %pa%s\n",
1059		  &base, &size, nomap ? " (nomap)" : "");
1060	return -ENOSYS;
1061}
1062
1063void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
1064{
1065	WARN_ON(1);
1066	return NULL;
1067}
1068#endif
1069
1070bool __init early_init_dt_verify(void *params)
1071{
1072	if (!params)
1073		return false;
1074
1075	/* check device tree validity */
1076	if (fdt_check_header(params))
1077		return false;
1078
1079	/* Setup flat device-tree pointer */
1080	initial_boot_params = params;
 
1081	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1082				fdt_totalsize(initial_boot_params));
 
 
 
 
1083	return true;
1084}
1085
1086
1087void __init early_init_dt_scan_nodes(void)
1088{
 
 
1089	/* Retrieve various information from the /chosen node */
1090	of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
 
 
1091
1092	/* Initialize {size,address}-cells info */
1093	of_scan_flat_dt(early_init_dt_scan_root, NULL);
1094
1095	/* Setup memory, calling early_init_dt_add_memory_arch */
1096	of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1097}
1098
1099bool __init early_init_dt_scan(void *params)
1100{
1101	bool status;
1102
1103	status = early_init_dt_verify(params);
1104	if (!status)
1105		return false;
1106
1107	early_init_dt_scan_nodes();
1108	return true;
1109}
1110
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1111/**
1112 * unflatten_device_tree - create tree of device_nodes from flat blob
1113 *
1114 * unflattens the device-tree passed by the firmware, creating the
1115 * tree of struct device_node. It also fills the "name" and "type"
1116 * pointers of the nodes so the normal device-tree walking functions
1117 * can be used.
1118 */
1119void __init unflatten_device_tree(void)
1120{
1121	__unflatten_device_tree(initial_boot_params, &of_root,
1122				early_init_dt_alloc_memory_arch);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1123
1124	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1125	of_alias_scan(early_init_dt_alloc_memory_arch);
 
 
1126}
1127
1128/**
1129 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1130 *
1131 * Copies and unflattens the device-tree passed by the firmware, creating the
1132 * tree of struct device_node. It also fills the "name" and "type"
1133 * pointers of the nodes so the normal device-tree walking functions
1134 * can be used. This should only be used when the FDT memory has not been
1135 * reserved such is the case when the FDT is built-in to the kernel init
1136 * section. If the FDT memory is reserved already then unflatten_device_tree
1137 * should be used instead.
1138 */
1139void __init unflatten_and_copy_device_tree(void)
1140{
1141	int size;
1142	void *dt;
1143
1144	if (!initial_boot_params) {
1145		pr_warn("No valid device tree found, continuing without\n");
1146		return;
1147	}
1148
1149	size = fdt_totalsize(initial_boot_params);
1150	dt = early_init_dt_alloc_memory_arch(size,
1151					     roundup_pow_of_two(FDT_V17_SIZE));
1152
1153	if (dt) {
1154		memcpy(dt, initial_boot_params, size);
1155		initial_boot_params = dt;
1156	}
1157	unflatten_device_tree();
1158}
1159
1160#ifdef CONFIG_SYSFS
1161static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1162			       struct bin_attribute *bin_attr,
1163			       char *buf, loff_t off, size_t count)
1164{
1165	memcpy(buf, initial_boot_params + off, count);
1166	return count;
1167}
1168
1169static int __init of_fdt_raw_init(void)
1170{
1171	static struct bin_attribute of_fdt_raw_attr =
1172		__BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1173
1174	if (!initial_boot_params)
1175		return 0;
1176
1177	if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1178				     fdt_totalsize(initial_boot_params))) {
1179		pr_warn("fdt: not creating '/sys/firmware/fdt': CRC check failed\n");
1180		return 0;
1181	}
1182	of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1183	return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1184}
1185late_initcall(of_fdt_raw_init);
1186#endif
1187
1188#endif /* CONFIG_OF_EARLY_FLATTREE */