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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 */
v4.10.11
 
   1/*
   2 * Functions for working with the Flattened Device Tree data format
   3 *
   4 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
   5 * benh@kernel.crashing.org
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * version 2 as published by the Free Software Foundation.
  10 */
  11
  12#define pr_fmt(fmt)	"OF: fdt:" fmt
  13
 
  14#include <linux/crc32.h>
  15#include <linux/kernel.h>
  16#include <linux/initrd.h>
  17#include <linux/memblock.h>
  18#include <linux/mutex.h>
  19#include <linux/of.h>
  20#include <linux/of_fdt.h>
  21#include <linux/of_reserved_mem.h>
  22#include <linux/sizes.h>
  23#include <linux/string.h>
  24#include <linux/errno.h>
  25#include <linux/slab.h>
  26#include <linux/libfdt.h>
  27#include <linux/debugfs.h>
  28#include <linux/serial_core.h>
  29#include <linux/sysfs.h>
 
  30
  31#include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
  32#include <asm/page.h>
  33
 
 
 
 
 
 
 
 
 
  34/*
  35 * of_fdt_limit_memory - limit the number of regions in the /memory node
  36 * @limit: maximum entries
  37 *
  38 * Adjust the flattened device tree to have at most 'limit' number of
  39 * memory entries in the /memory node. This function may be called
  40 * any time after initial_boot_param is set.
  41 */
  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 uint32_t *addr_prop;
  50	const uint32_t *size_prop;
  51	int root_offset;
  52	int cell_size;
  53
  54	root_offset = fdt_path_offset(initial_boot_params, "/");
  55	if (root_offset < 0)
  56		return;
  57
  58	addr_prop = fdt_getprop(initial_boot_params, root_offset,
  59				"#address-cells", NULL);
  60	if (addr_prop)
  61		nr_address_cells = fdt32_to_cpu(*addr_prop);
  62
  63	size_prop = fdt_getprop(initial_boot_params, root_offset,
  64				"#size-cells", NULL);
  65	if (size_prop)
  66		nr_size_cells = fdt32_to_cpu(*size_prop);
  67
  68	cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
  69
  70	memory = fdt_path_offset(initial_boot_params, "/memory");
  71	if (memory > 0) {
  72		val = fdt_getprop(initial_boot_params, memory, "reg", &len);
  73		if (len > limit*cell_size) {
  74			len = limit*cell_size;
  75			pr_debug("Limiting number of entries to %d\n", limit);
  76			fdt_setprop(initial_boot_params, memory, "reg", val,
  77					len);
  78		}
  79	}
  80}
  81
  82/**
  83 * of_fdt_is_compatible - Return true if given node from the given blob has
  84 * compat in its compatible list
  85 * @blob: A device tree blob
  86 * @node: node to test
  87 * @compat: compatible string to compare with compatible list.
  88 *
  89 * On match, returns a non-zero value with smaller values returned for more
  90 * specific compatible values.
  91 */
  92int 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
 133/**
 134 * of_fdt_match - Return true if node matches a list of compatible values
 135 */
 136int of_fdt_match(const void *blob, unsigned long node,
 137                 const char *const *compat)
 138{
 139	unsigned int tmp, score = 0;
 140
 141	if (!compat)
 142		return 0;
 143
 144	while (*compat) {
 145		tmp = of_fdt_is_compatible(blob, node, *compat);
 146		if (tmp && (score == 0 || (tmp < score)))
 147			score = tmp;
 148		compat++;
 149	}
 150
 151	return score;
 152}
 153
 154static void *unflatten_dt_alloc(void **mem, unsigned long size,
 155				       unsigned long align)
 156{
 157	void *res;
 158
 159	*mem = PTR_ALIGN(*mem, align);
 160	res = *mem;
 161	*mem += size;
 162
 163	return res;
 164}
 165
 166static void populate_properties(const void *blob,
 167				int offset,
 168				void **mem,
 169				struct device_node *np,
 170				const char *nodename,
 171				bool dryrun)
 172{
 173	struct property *pp, **pprev = NULL;
 174	int cur;
 175	bool has_name = false;
 176
 177	pprev = &np->properties;
 178	for (cur = fdt_first_property_offset(blob, offset);
 179	     cur >= 0;
 180	     cur = fdt_next_property_offset(blob, cur)) {
 181		const __be32 *val;
 182		const char *pname;
 183		u32 sz;
 184
 185		val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
 186		if (!val) {
 187			pr_warn("Cannot locate property at 0x%x\n", cur);
 188			continue;
 189		}
 190
 191		if (!pname) {
 192			pr_warn("Cannot find property name at 0x%x\n", cur);
 193			continue;
 194		}
 195
 196		if (!strcmp(pname, "name"))
 197			has_name = true;
 198
 199		pp = unflatten_dt_alloc(mem, sizeof(struct property),
 200					__alignof__(struct property));
 201		if (dryrun)
 202			continue;
 203
 204		/* We accept flattened tree phandles either in
 205		 * ePAPR-style "phandle" properties, or the
 206		 * legacy "linux,phandle" properties.  If both
 207		 * appear and have different values, things
 208		 * will get weird. Don't do that.
 209		 */
 210		if (!strcmp(pname, "phandle") ||
 211		    !strcmp(pname, "linux,phandle")) {
 212			if (!np->phandle)
 213				np->phandle = be32_to_cpup(val);
 214		}
 215
 216		/* And we process the "ibm,phandle" property
 217		 * used in pSeries dynamic device tree
 218		 * stuff
 219		 */
 220		if (!strcmp(pname, "ibm,phandle"))
 221			np->phandle = be32_to_cpup(val);
 222
 223		pp->name   = (char *)pname;
 224		pp->length = sz;
 225		pp->value  = (__be32 *)val;
 226		*pprev     = pp;
 227		pprev      = &pp->next;
 228	}
 229
 230	/* With version 0x10 we may not have the name property,
 231	 * recreate it here from the unit name if absent
 232	 */
 233	if (!has_name) {
 234		const char *p = nodename, *ps = p, *pa = NULL;
 235		int len;
 236
 237		while (*p) {
 238			if ((*p) == '@')
 239				pa = p;
 240			else if ((*p) == '/')
 241				ps = p + 1;
 242			p++;
 243		}
 244
 245		if (pa < ps)
 246			pa = p;
 247		len = (pa - ps) + 1;
 248		pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
 249					__alignof__(struct property));
 250		if (!dryrun) {
 251			pp->name   = "name";
 252			pp->length = len;
 253			pp->value  = pp + 1;
 254			*pprev     = pp;
 255			pprev      = &pp->next;
 256			memcpy(pp->value, ps, len - 1);
 257			((char *)pp->value)[len - 1] = 0;
 258			pr_debug("fixed up name for %s -> %s\n",
 259				 nodename, (char *)pp->value);
 260		}
 261	}
 262
 263	if (!dryrun)
 264		*pprev = NULL;
 265}
 266
 267static unsigned int populate_node(const void *blob,
 268				  int offset,
 269				  void **mem,
 270				  struct device_node *dad,
 271				  unsigned int fpsize,
 272				  struct device_node **pnp,
 273				  bool dryrun)
 274{
 275	struct device_node *np;
 276	const char *pathp;
 277	unsigned int l, allocl;
 278	int new_format = 0;
 279
 280	pathp = fdt_get_name(blob, offset, &l);
 281	if (!pathp) {
 282		*pnp = NULL;
 283		return 0;
 284	}
 285
 286	allocl = ++l;
 287
 288	/* version 0x10 has a more compact unit name here instead of the full
 289	 * path. we accumulate the full path size using "fpsize", we'll rebuild
 290	 * it later. We detect this because the first character of the name is
 291	 * not '/'.
 292	 */
 293	if ((*pathp) != '/') {
 294		new_format = 1;
 295		if (fpsize == 0) {
 296			/* root node: special case. fpsize accounts for path
 297			 * plus terminating zero. root node only has '/', so
 298			 * fpsize should be 2, but we want to avoid the first
 299			 * level nodes to have two '/' so we use fpsize 1 here
 300			 */
 301			fpsize = 1;
 302			allocl = 2;
 303			l = 1;
 304			pathp = "";
 305		} else {
 306			/* account for '/' and path size minus terminal 0
 307			 * already in 'l'
 308			 */
 309			fpsize += l;
 310			allocl = fpsize;
 311		}
 312	}
 313
 314	np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
 315				__alignof__(struct device_node));
 316	if (!dryrun) {
 317		char *fn;
 318		of_node_init(np);
 319		np->full_name = fn = ((char *)np) + sizeof(*np);
 320		if (new_format) {
 321			/* rebuild full path for new format */
 322			if (dad && dad->parent) {
 323				strcpy(fn, dad->full_name);
 324#ifdef DEBUG
 325				if ((strlen(fn) + l + 1) != allocl) {
 326					pr_debug("%s: p: %d, l: %d, a: %d\n",
 327						pathp, (int)strlen(fn),
 328						l, allocl);
 329				}
 330#endif
 331				fn += strlen(fn);
 332			}
 333			*(fn++) = '/';
 334		}
 335		memcpy(fn, pathp, l);
 336
 337		if (dad != NULL) {
 338			np->parent = dad;
 339			np->sibling = dad->child;
 340			dad->child = np;
 341		}
 342	}
 343
 344	populate_properties(blob, offset, mem, np, pathp, dryrun);
 345	if (!dryrun) {
 346		np->name = of_get_property(np, "name", NULL);
 347		np->type = of_get_property(np, "device_type", NULL);
 348
 349		if (!np->name)
 350			np->name = "<NULL>";
 351		if (!np->type)
 352			np->type = "<NULL>";
 353	}
 354
 355	*pnp = np;
 356	return fpsize;
 357}
 358
 359static void reverse_nodes(struct device_node *parent)
 360{
 361	struct device_node *child, *next;
 362
 363	/* In-depth first */
 364	child = parent->child;
 365	while (child) {
 366		reverse_nodes(child);
 367
 368		child = child->sibling;
 369	}
 370
 371	/* Reverse the nodes in the child list */
 372	child = parent->child;
 373	parent->child = NULL;
 374	while (child) {
 375		next = child->sibling;
 376
 377		child->sibling = parent->child;
 378		parent->child = child;
 379		child = next;
 380	}
 381}
 382
 383/**
 384 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
 385 * @blob: The parent device tree blob
 386 * @mem: Memory chunk to use for allocating device nodes and properties
 387 * @dad: Parent struct device_node
 388 * @nodepp: The device_node tree created by the call
 389 *
 390 * It returns the size of unflattened device tree or error code
 391 */
 392static int unflatten_dt_nodes(const void *blob,
 393			      void *mem,
 394			      struct device_node *dad,
 395			      struct device_node **nodepp)
 396{
 397	struct device_node *root;
 398	int offset = 0, depth = 0, initial_depth = 0;
 399#define FDT_MAX_DEPTH	64
 400	unsigned int fpsizes[FDT_MAX_DEPTH];
 401	struct device_node *nps[FDT_MAX_DEPTH];
 402	void *base = mem;
 403	bool dryrun = !base;
 
 404
 405	if (nodepp)
 406		*nodepp = NULL;
 407
 408	/*
 409	 * We're unflattening device sub-tree if @dad is valid. There are
 410	 * possibly multiple nodes in the first level of depth. We need
 411	 * set @depth to 1 to make fdt_next_node() happy as it bails
 412	 * immediately when negative @depth is found. Otherwise, the device
 413	 * nodes except the first one won't be unflattened successfully.
 414	 */
 415	if (dad)
 416		depth = initial_depth = 1;
 417
 418	root = dad;
 419	fpsizes[depth] = dad ? strlen(of_node_full_name(dad)) : 0;
 420	nps[depth] = dad;
 421
 422	for (offset = 0;
 423	     offset >= 0 && depth >= initial_depth;
 424	     offset = fdt_next_node(blob, offset, &depth)) {
 425		if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
 426			continue;
 427
 428		fpsizes[depth+1] = populate_node(blob, offset, &mem,
 429						 nps[depth],
 430						 fpsizes[depth],
 431						 &nps[depth+1], dryrun);
 432		if (!fpsizes[depth+1])
 433			return mem - base;
 
 
 434
 435		if (!dryrun && nodepp && !*nodepp)
 436			*nodepp = nps[depth+1];
 437		if (!dryrun && !root)
 438			root = nps[depth+1];
 439	}
 440
 441	if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 442		pr_err("Error %d processing FDT\n", offset);
 443		return -EINVAL;
 444	}
 445
 446	/*
 447	 * Reverse the child list. Some drivers assumes node order matches .dts
 448	 * node order
 449	 */
 450	if (!dryrun)
 451		reverse_nodes(root);
 452
 453	return mem - base;
 454}
 455
 456/**
 457 * __unflatten_device_tree - create tree of device_nodes from flat blob
 458 *
 459 * unflattens a device-tree, creating the
 460 * tree of struct device_node. It also fills the "name" and "type"
 461 * pointers of the nodes so the normal device-tree walking functions
 462 * can be used.
 463 * @blob: The blob to expand
 464 * @dad: Parent device node
 465 * @mynodes: The device_node tree created by the call
 466 * @dt_alloc: An allocator that provides a virtual address to memory
 467 * for the resulting tree
 
 468 *
 469 * Returns NULL on failure or the memory chunk containing the unflattened
 
 
 
 
 470 * device tree on success.
 471 */
 472static void *__unflatten_device_tree(const void *blob,
 473				     struct device_node *dad,
 474				     struct device_node **mynodes,
 475				     void *(*dt_alloc)(u64 size, u64 align),
 476				     bool detached)
 477{
 478	int size;
 479	void *mem;
 
 
 
 
 480
 481	pr_debug(" -> unflatten_device_tree()\n");
 482
 483	if (!blob) {
 484		pr_debug("No device tree pointer\n");
 485		return NULL;
 486	}
 487
 488	pr_debug("Unflattening device tree:\n");
 489	pr_debug("magic: %08x\n", fdt_magic(blob));
 490	pr_debug("size: %08x\n", fdt_totalsize(blob));
 491	pr_debug("version: %08x\n", fdt_version(blob));
 492
 493	if (fdt_check_header(blob)) {
 494		pr_err("Invalid device tree blob header\n");
 495		return NULL;
 496	}
 497
 498	/* First pass, scan for size */
 499	size = unflatten_dt_nodes(blob, NULL, dad, NULL);
 500	if (size < 0)
 501		return NULL;
 502
 503	size = ALIGN(size, 4);
 504	pr_debug("  size is %d, allocating...\n", size);
 505
 506	/* Allocate memory for the expanded device tree */
 507	mem = dt_alloc(size + 4, __alignof__(struct device_node));
 
 
 
 508	memset(mem, 0, size);
 509
 510	*(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
 511
 512	pr_debug("  unflattening %p...\n", mem);
 513
 514	/* Second pass, do actual unflattening */
 515	unflatten_dt_nodes(blob, mem, dad, mynodes);
 
 516	if (be32_to_cpup(mem + size) != 0xdeadbeef)
 517		pr_warning("End of tree marker overwritten: %08x\n",
 518			   be32_to_cpup(mem + size));
 
 
 
 519
 520	if (detached && mynodes) {
 521		of_node_set_flag(*mynodes, OF_DETACHED);
 522		pr_debug("unflattened tree is detached\n");
 523	}
 524
 525	pr_debug(" <- unflatten_device_tree()\n");
 526	return mem;
 527}
 528
 529static void *kernel_tree_alloc(u64 size, u64 align)
 530{
 531	return kzalloc(size, GFP_KERNEL);
 532}
 533
 534static DEFINE_MUTEX(of_fdt_unflatten_mutex);
 535
 536/**
 537 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 538 * @blob: Flat device tree blob
 539 * @dad: Parent device node
 540 * @mynodes: The device tree created by the call
 541 *
 542 * unflattens the device-tree passed by the firmware, creating the
 543 * tree of struct device_node. It also fills the "name" and "type"
 544 * pointers of the nodes so the normal device-tree walking functions
 545 * can be used.
 546 *
 547 * Returns NULL on failure or the memory chunk containing the unflattened
 548 * device tree on success.
 549 */
 550void *of_fdt_unflatten_tree(const unsigned long *blob,
 551			    struct device_node *dad,
 552			    struct device_node **mynodes)
 553{
 554	void *mem;
 555
 556	mutex_lock(&of_fdt_unflatten_mutex);
 557	mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
 558				      true);
 559	mutex_unlock(&of_fdt_unflatten_mutex);
 560
 561	return mem;
 562}
 563EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
 564
 565/* Everything below here references initial_boot_params directly. */
 566int __initdata dt_root_addr_cells;
 567int __initdata dt_root_size_cells;
 568
 569void *initial_boot_params;
 
 570
 571#ifdef CONFIG_OF_EARLY_FLATTREE
 572
 573static u32 of_fdt_crc32;
 574
 575/**
 576 * res_mem_reserve_reg() - reserve all memory described in 'reg' property
 
 
 
 
 
 577 */
 578static int __init __reserved_mem_reserve_reg(unsigned long node,
 579					     const char *uname)
 580{
 581	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
 582	phys_addr_t base, size;
 583	int len;
 584	const __be32 *prop;
 585	int nomap, first = 1;
 586
 587	prop = of_get_flat_dt_prop(node, "reg", &len);
 588	if (!prop)
 589		return -ENOENT;
 590
 591	if (len && len % t_len != 0) {
 592		pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
 593		       uname);
 594		return -EINVAL;
 595	}
 596
 597	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 598
 599	while (len >= t_len) {
 600		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 601		size = dt_mem_next_cell(dt_root_size_cells, &prop);
 602
 603		if (size &&
 604		    early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
 605			pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
 606				uname, &base, (unsigned long)size / SZ_1M);
 607		else
 608			pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
 609				uname, &base, (unsigned long)size / SZ_1M);
 610
 611		len -= t_len;
 612		if (first) {
 613			fdt_reserved_mem_save_node(node, uname, base, size);
 614			first = 0;
 615		}
 616	}
 617	return 0;
 618}
 619
 620/**
 621 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
 622 * in /reserved-memory matches the values supported by the current implementation,
 623 * also check if ranges property has been provided
 624 */
 625static int __init __reserved_mem_check_root(unsigned long node)
 626{
 627	const __be32 *prop;
 628
 629	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 630	if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
 631		return -EINVAL;
 632
 633	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 634	if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
 635		return -EINVAL;
 636
 637	prop = of_get_flat_dt_prop(node, "ranges", NULL);
 638	if (!prop)
 639		return -EINVAL;
 640	return 0;
 641}
 642
 643/**
 644 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
 645 */
 646static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
 647					  int depth, void *data)
 648{
 649	static int found;
 650	const char *status;
 651	int err;
 652
 653	if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
 654		if (__reserved_mem_check_root(node) != 0) {
 655			pr_err("Reserved memory: unsupported node format, ignoring\n");
 656			/* break scan */
 657			return 1;
 658		}
 659		found = 1;
 660		/* scan next node */
 661		return 0;
 662	} else if (!found) {
 663		/* scan next node */
 664		return 0;
 665	} else if (found && depth < 2) {
 666		/* scanning of /reserved-memory has been finished */
 667		return 1;
 668	}
 669
 670	status = of_get_flat_dt_prop(node, "status", NULL);
 671	if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
 672		return 0;
 673
 674	err = __reserved_mem_reserve_reg(node, uname);
 675	if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
 676		fdt_reserved_mem_save_node(node, uname, 0, 0);
 677
 678	/* scan next node */
 679	return 0;
 680}
 681
 682/**
 683 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
 684 *
 685 * This function grabs memory from early allocator for device exclusive use
 686 * defined in device tree structures. It should be called by arch specific code
 687 * once the early allocator (i.e. memblock) has been fully activated.
 688 */
 689void __init early_init_fdt_scan_reserved_mem(void)
 690{
 691	int n;
 692	u64 base, size;
 693
 694	if (!initial_boot_params)
 695		return;
 696
 
 
 
 697	/* Process header /memreserve/ fields */
 698	for (n = 0; ; n++) {
 699		fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
 700		if (!size)
 701			break;
 702		early_init_dt_reserve_memory_arch(base, size, 0);
 703	}
 704
 705	of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
 706	fdt_init_reserved_mem();
 707}
 708
 709/**
 710 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
 711 */
 712void __init early_init_fdt_reserve_self(void)
 713{
 714	if (!initial_boot_params)
 715		return;
 716
 717	/* Reserve the dtb region */
 718	early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
 719					  fdt_totalsize(initial_boot_params),
 720					  0);
 721}
 722
 723/**
 724 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 725 * @it: callback function
 726 * @data: context data pointer
 727 *
 728 * This function is used to scan the flattened device-tree, it is
 729 * used to extract the memory information at boot before we can
 730 * unflatten the tree
 731 */
 732int __init of_scan_flat_dt(int (*it)(unsigned long node,
 733				     const char *uname, int depth,
 734				     void *data),
 735			   void *data)
 736{
 737	const void *blob = initial_boot_params;
 738	const char *pathp;
 739	int offset, rc = 0, depth = -1;
 740
 741        for (offset = fdt_next_node(blob, -1, &depth);
 742             offset >= 0 && depth >= 0 && !rc;
 743             offset = fdt_next_node(blob, offset, &depth)) {
 
 
 
 744
 745		pathp = fdt_get_name(blob, offset, NULL);
 746		if (*pathp == '/')
 747			pathp = kbasename(pathp);
 748		rc = it(offset, pathp, depth, data);
 749	}
 750	return rc;
 751}
 752
 753/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 754 * of_get_flat_dt_subnode_by_name - get the subnode by given name
 755 *
 756 * @node: the parent node
 757 * @uname: the name of subnode
 758 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
 759 */
 760
 761int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
 762{
 763	return fdt_subnode_offset(initial_boot_params, node, uname);
 764}
 765
 766/**
 767 * of_get_flat_dt_root - find the root node in the flat blob
 768 */
 769unsigned long __init of_get_flat_dt_root(void)
 770{
 771	return 0;
 772}
 773
 774/**
 775 * of_get_flat_dt_size - Return the total size of the FDT
 776 */
 777int __init of_get_flat_dt_size(void)
 778{
 779	return fdt_totalsize(initial_boot_params);
 780}
 781
 782/**
 783 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 784 *
 785 * This function can be used within scan_flattened_dt callback to get
 786 * access to properties
 787 */
 788const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 789				       int *size)
 790{
 791	return fdt_getprop(initial_boot_params, node, name, size);
 792}
 793
 794/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 795 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 796 * @node: node to test
 797 * @compat: compatible string to compare with compatible list.
 798 */
 799int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 800{
 801	return of_fdt_is_compatible(initial_boot_params, node, compat);
 802}
 803
 804/**
 805 * of_flat_dt_match - Return true if node matches a list of compatible values
 806 */
 807int __init of_flat_dt_match(unsigned long node, const char *const *compat)
 808{
 809	return of_fdt_match(initial_boot_params, node, compat);
 
 
 
 
 
 
 
 
 
 
 
 
 810}
 811
 812struct fdt_scan_status {
 813	const char *name;
 814	int namelen;
 815	int depth;
 816	int found;
 817	int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
 818	void *data;
 819};
 820
 821const char * __init of_flat_dt_get_machine_name(void)
 822{
 823	const char *name;
 824	unsigned long dt_root = of_get_flat_dt_root();
 825
 826	name = of_get_flat_dt_prop(dt_root, "model", NULL);
 827	if (!name)
 828		name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
 829	return name;
 830}
 831
 832/**
 833 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
 834 *
 835 * @default_match: A machine specific ptr to return in case of no match.
 836 * @get_next_compat: callback function to return next compatible match table.
 837 *
 838 * Iterate through machine match tables to find the best match for the machine
 839 * compatible string in the FDT.
 840 */
 841const void * __init of_flat_dt_match_machine(const void *default_match,
 842		const void * (*get_next_compat)(const char * const**))
 843{
 844	const void *data = NULL;
 845	const void *best_data = default_match;
 846	const char *const *compat;
 847	unsigned long dt_root;
 848	unsigned int best_score = ~1, score = 0;
 849
 850	dt_root = of_get_flat_dt_root();
 851	while ((data = get_next_compat(&compat))) {
 852		score = of_flat_dt_match(dt_root, compat);
 853		if (score > 0 && score < best_score) {
 854			best_data = data;
 855			best_score = score;
 856		}
 857	}
 858	if (!best_data) {
 859		const char *prop;
 860		int size;
 861
 862		pr_err("\n unrecognized device tree list:\n[ ");
 863
 864		prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
 865		if (prop) {
 866			while (size > 0) {
 867				printk("'%s' ", prop);
 868				size -= strlen(prop) + 1;
 869				prop += strlen(prop) + 1;
 870			}
 871		}
 872		printk("]\n\n");
 873		return NULL;
 874	}
 875
 876	pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
 877
 878	return best_data;
 879}
 880
 881#ifdef CONFIG_BLK_DEV_INITRD
 882#ifndef __early_init_dt_declare_initrd
 883static void __early_init_dt_declare_initrd(unsigned long start,
 884					   unsigned long end)
 885{
 886	initrd_start = (unsigned long)__va(start);
 887	initrd_end = (unsigned long)__va(end);
 888	initrd_below_start_ok = 1;
 
 
 
 
 
 
 
 
 889}
 890#endif
 891
 892/**
 893 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 894 * @node: reference to node containing initrd location ('chosen')
 895 */
 896static void __init early_init_dt_check_for_initrd(unsigned long node)
 897{
 898	u64 start, end;
 899	int len;
 900	const __be32 *prop;
 901
 
 
 
 902	pr_debug("Looking for initrd properties... ");
 903
 904	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 905	if (!prop)
 906		return;
 907	start = of_read_number(prop, len/4);
 908
 909	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 910	if (!prop)
 911		return;
 912	end = of_read_number(prop, len/4);
 
 
 913
 914	__early_init_dt_declare_initrd(start, end);
 
 
 915
 916	pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
 917		 (unsigned long long)start, (unsigned long long)end);
 918}
 919#else
 920static inline void early_init_dt_check_for_initrd(unsigned long node)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 921{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 922}
 923#endif /* CONFIG_BLK_DEV_INITRD */
 924
 925#ifdef CONFIG_SERIAL_EARLYCON
 926
 927int __init early_init_dt_scan_chosen_stdout(void)
 928{
 929	int offset;
 930	const char *p, *q, *options = NULL;
 931	int l;
 932	const struct earlycon_id *match;
 933	const void *fdt = initial_boot_params;
 
 934
 935	offset = fdt_path_offset(fdt, "/chosen");
 936	if (offset < 0)
 937		offset = fdt_path_offset(fdt, "/chosen@0");
 938	if (offset < 0)
 939		return -ENOENT;
 940
 941	p = fdt_getprop(fdt, offset, "stdout-path", &l);
 942	if (!p)
 943		p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
 944	if (!p || !l)
 945		return -ENOENT;
 946
 947	q = strchrnul(p, ':');
 948	if (*q != '\0')
 949		options = q + 1;
 950	l = q - p;
 951
 952	/* Get the node specified by stdout-path */
 953	offset = fdt_path_offset_namelen(fdt, p, l);
 954	if (offset < 0) {
 955		pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
 956		return 0;
 957	}
 958
 959	for (match = __earlycon_table; match < __earlycon_table_end; match++) {
 960		if (!match->compatible[0])
 961			continue;
 962
 963		if (fdt_node_check_compatible(fdt, offset, match->compatible))
 964			continue;
 965
 966		of_setup_earlycon(match, offset, options);
 967		return 0;
 
 968	}
 969	return -ENODEV;
 970}
 971#endif
 972
 973/**
 974 * early_init_dt_scan_root - fetch the top level address and size cells
 975 */
 976int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 977				   int depth, void *data)
 978{
 979	const __be32 *prop;
 
 
 980
 981	if (depth != 0)
 982		return 0;
 983
 984	dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 985	dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 986
 987	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 988	if (prop)
 989		dt_root_size_cells = be32_to_cpup(prop);
 990	pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 991
 992	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 993	if (prop)
 994		dt_root_addr_cells = be32_to_cpup(prop);
 995	pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 996
 997	/* break now */
 998	return 1;
 999}
1000
1001u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
1002{
1003	const __be32 *p = *cellp;
1004
1005	*cellp = p + s;
1006	return of_read_number(p, s);
1007}
1008
1009/**
1010 * early_init_dt_scan_memory - Look for an parse memory nodes
1011 */
1012int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
1013				     int depth, void *data)
1014{
1015	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
1016	const __be32 *reg, *endp;
1017	int l;
1018	bool hotpluggable;
 
 
 
 
 
 
 
 
 
 
 
1019
1020	/* We are scanning "memory" nodes only */
1021	if (type == NULL) {
1022		/*
1023		 * The longtrail doesn't have a device_type on the
1024		 * /memory node, so look for the node called /memory@0.
1025		 */
1026		if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0)
1027			return 0;
1028	} else if (strcmp(type, "memory") != 0)
1029		return 0;
1030
1031	reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1032	if (reg == NULL)
1033		reg = of_get_flat_dt_prop(node, "reg", &l);
1034	if (reg == NULL)
1035		return 0;
1036
1037	endp = reg + (l / sizeof(__be32));
1038	hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1039
1040	pr_debug("memory scan node %s, reg size %d,\n", uname, l);
 
1041
1042	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1043		u64 base, size;
1044
1045		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
1046		size = dt_mem_next_cell(dt_root_size_cells, &reg);
 
1047
1048		if (size == 0)
1049			continue;
1050		pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
1051		    (unsigned long long)size);
1052
1053		early_init_dt_add_memory_arch(base, size);
1054
1055		if (!hotpluggable)
1056			continue;
1057
1058		if (early_init_dt_mark_hotplug_memory_arch(base, size))
1059			pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1060				base, base + size);
 
1061	}
1062
1063	return 0;
1064}
1065
1066int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
1067				     int depth, void *data)
1068{
1069	int l;
1070	const char *p;
 
 
1071
1072	pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
 
 
 
 
 
1073
1074	if (depth != 1 || !data ||
1075	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
1076		return 0;
1077
1078	early_init_dt_check_for_initrd(node);
 
 
 
 
 
 
 
 
 
 
 
 
 
1079
1080	/* Retrieve command line */
1081	p = of_get_flat_dt_prop(node, "bootargs", &l);
1082	if (p != NULL && l > 0)
1083		strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
1084
 
1085	/*
1086	 * CONFIG_CMDLINE is meant to be a default in case nothing else
1087	 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1088	 * is set in which case we override whatever was found earlier.
1089	 */
1090#ifdef CONFIG_CMDLINE
1091#if defined(CONFIG_CMDLINE_EXTEND)
1092	strlcat(data, " ", COMMAND_LINE_SIZE);
1093	strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1094#elif defined(CONFIG_CMDLINE_FORCE)
1095	strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1096#else
1097	/* No arguments from boot loader, use kernel's  cmdl*/
1098	if (!((char *)data)[0])
1099		strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1100#endif
1101#endif /* CONFIG_CMDLINE */
1102
1103	pr_debug("Command line is: %s\n", (char*)data);
1104
1105	/* break now */
1106	return 1;
1107}
1108
1109#ifdef CONFIG_HAVE_MEMBLOCK
1110#ifndef MIN_MEMBLOCK_ADDR
1111#define MIN_MEMBLOCK_ADDR	__pa(PAGE_OFFSET)
1112#endif
1113#ifndef MAX_MEMBLOCK_ADDR
1114#define MAX_MEMBLOCK_ADDR	((phys_addr_t)~0)
1115#endif
1116
1117void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1118{
1119	const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1120
 
 
 
 
 
 
1121	if (!PAGE_ALIGNED(base)) {
1122		if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1123			pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1124				base, base + size);
1125			return;
1126		}
1127		size -= PAGE_SIZE - (base & ~PAGE_MASK);
1128		base = PAGE_ALIGN(base);
1129	}
1130	size &= PAGE_MASK;
1131
1132	if (base > MAX_MEMBLOCK_ADDR) {
1133		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1134				base, base + size);
1135		return;
1136	}
1137
1138	if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1139		pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1140				((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1141		size = MAX_MEMBLOCK_ADDR - base + 1;
1142	}
1143
1144	if (base + size < phys_offset) {
1145		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1146			   base, base + size);
1147		return;
1148	}
1149	if (base < phys_offset) {
1150		pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1151			   base, phys_offset);
1152		size -= phys_offset - base;
1153		base = phys_offset;
1154	}
1155	memblock_add(base, size);
1156}
1157
1158int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1159{
1160	return memblock_mark_hotplug(base, size);
1161}
1162
1163int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1164					phys_addr_t size, bool nomap)
1165{
1166	if (nomap)
1167		return memblock_remove(base, size);
1168	return memblock_reserve(base, size);
1169}
1170
1171/*
1172 * called from unflatten_device_tree() to bootstrap devicetree itself
1173 * Architectures can override this definition if memblock isn't used
1174 */
1175void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
1176{
1177	return __va(memblock_alloc(size, align));
1178}
1179#else
1180void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1181{
1182	WARN_ON(1);
1183}
1184
1185int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1186{
1187	return -ENOSYS;
1188}
1189
1190int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1191					phys_addr_t size, bool nomap)
1192{
1193	pr_err("Reserved memory not supported, ignoring range %pa - %pa%s\n",
1194		  &base, &size, nomap ? " (nomap)" : "");
1195	return -ENOSYS;
1196}
1197
1198void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
1199{
1200	WARN_ON(1);
1201	return NULL;
1202}
1203#endif
1204
1205bool __init early_init_dt_verify(void *params)
1206{
1207	if (!params)
1208		return false;
1209
1210	/* check device tree validity */
1211	if (fdt_check_header(params))
1212		return false;
1213
1214	/* Setup flat device-tree pointer */
1215	initial_boot_params = params;
 
1216	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1217				fdt_totalsize(initial_boot_params));
 
 
 
 
1218	return true;
1219}
1220
1221
1222void __init early_init_dt_scan_nodes(void)
1223{
 
 
1224	/* Retrieve various information from the /chosen node */
1225	of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
 
 
1226
1227	/* Initialize {size,address}-cells info */
1228	of_scan_flat_dt(early_init_dt_scan_root, NULL);
1229
1230	/* Setup memory, calling early_init_dt_add_memory_arch */
1231	of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1232}
1233
1234bool __init early_init_dt_scan(void *params)
1235{
1236	bool status;
1237
1238	status = early_init_dt_verify(params);
1239	if (!status)
1240		return false;
1241
1242	early_init_dt_scan_nodes();
1243	return true;
1244}
1245
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1246/**
1247 * unflatten_device_tree - create tree of device_nodes from flat blob
1248 *
1249 * unflattens the device-tree passed by the firmware, creating the
1250 * tree of struct device_node. It also fills the "name" and "type"
1251 * pointers of the nodes so the normal device-tree walking functions
1252 * can be used.
1253 */
1254void __init unflatten_device_tree(void)
1255{
1256	__unflatten_device_tree(initial_boot_params, NULL, &of_root,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1257				early_init_dt_alloc_memory_arch, false);
1258
1259	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1260	of_alias_scan(early_init_dt_alloc_memory_arch);
 
 
1261}
1262
1263/**
1264 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1265 *
1266 * Copies and unflattens the device-tree passed by the firmware, creating the
1267 * tree of struct device_node. It also fills the "name" and "type"
1268 * pointers of the nodes so the normal device-tree walking functions
1269 * can be used. This should only be used when the FDT memory has not been
1270 * reserved such is the case when the FDT is built-in to the kernel init
1271 * section. If the FDT memory is reserved already then unflatten_device_tree
1272 * should be used instead.
1273 */
1274void __init unflatten_and_copy_device_tree(void)
1275{
1276	int size;
1277	void *dt;
1278
1279	if (!initial_boot_params) {
1280		pr_warn("No valid device tree found, continuing without\n");
1281		return;
1282	}
1283
1284	size = fdt_totalsize(initial_boot_params);
1285	dt = early_init_dt_alloc_memory_arch(size,
1286					     roundup_pow_of_two(FDT_V17_SIZE));
1287
1288	if (dt) {
1289		memcpy(dt, initial_boot_params, size);
1290		initial_boot_params = dt;
1291	}
1292	unflatten_device_tree();
1293}
1294
1295#ifdef CONFIG_SYSFS
1296static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1297			       struct bin_attribute *bin_attr,
1298			       char *buf, loff_t off, size_t count)
1299{
1300	memcpy(buf, initial_boot_params + off, count);
1301	return count;
1302}
1303
1304static int __init of_fdt_raw_init(void)
1305{
1306	static struct bin_attribute of_fdt_raw_attr =
1307		__BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1308
1309	if (!initial_boot_params)
1310		return 0;
1311
1312	if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1313				     fdt_totalsize(initial_boot_params))) {
1314		pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1315		return 0;
1316	}
1317	of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1318	return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1319}
1320late_initcall(of_fdt_raw_init);
1321#endif
1322
1323#endif /* CONFIG_OF_EARLY_FLATTREE */