1/*
   2 *	linux/kernel/resource.c
   3 *
   4 * Copyright (C) 1999	Linus Torvalds
   5 * Copyright (C) 1999	Martin Mares <mj@ucw.cz>
   6 *
   7 * Arbitrary resource management.
   8 */
   9
  10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12#include <linux/export.h>
  13#include <linux/errno.h>
  14#include <linux/ioport.h>
  15#include <linux/init.h>
  16#include <linux/slab.h>
  17#include <linux/spinlock.h>
  18#include <linux/fs.h>
  19#include <linux/proc_fs.h>
  20#include <linux/sched.h>
  21#include <linux/seq_file.h>
  22#include <linux/device.h>
  23#include <linux/pfn.h>
  24#include <linux/mm.h>
  25#include <linux/resource_ext.h>
  26#include <asm/io.h>
  27
  28
  29struct resource ioport_resource = {
  30	.name	= "PCI IO",
  31	.start	= 0,
  32	.end	= IO_SPACE_LIMIT,
  33	.flags	= IORESOURCE_IO,
  34};
  35EXPORT_SYMBOL(ioport_resource);
  36
  37struct resource iomem_resource = {
  38	.name	= "PCI mem",
  39	.start	= 0,
  40	.end	= -1,
  41	.flags	= IORESOURCE_MEM,
  42};
  43EXPORT_SYMBOL(iomem_resource);
  44
  45/* constraints to be met while allocating resources */
  46struct resource_constraint {
  47	resource_size_t min, max, align;
  48	resource_size_t (*alignf)(void *, const struct resource *,
  49			resource_size_t, resource_size_t);
  50	void *alignf_data;
  51};
  52
  53static DEFINE_RWLOCK(resource_lock);
  54
  55/*
  56 * For memory hotplug, there is no way to free resource entries allocated
  57 * by boot mem after the system is up. So for reusing the resource entry
  58 * we need to remember the resource.
  59 */
  60static struct resource *bootmem_resource_free;
  61static DEFINE_SPINLOCK(bootmem_resource_lock);
  62
  63static struct resource *next_resource(struct resource *p, bool sibling_only)
  64{
  65	/* Caller wants to traverse through siblings only */
  66	if (sibling_only)
  67		return p->sibling;
  68
  69	if (p->child)
  70		return p->child;
  71	while (!p->sibling && p->parent)
  72		p = p->parent;
  73	return p->sibling;
  74}
  75
  76static void *r_next(struct seq_file *m, void *v, loff_t *pos)
  77{
  78	struct resource *p = v;
  79	(*pos)++;
  80	return (void *)next_resource(p, false);
  81}
  82
  83#ifdef CONFIG_PROC_FS
  84
  85enum { MAX_IORES_LEVEL = 5 };
  86
  87static void *r_start(struct seq_file *m, loff_t *pos)
  88	__acquires(resource_lock)
  89{
  90	struct resource *p = m->private;
  91	loff_t l = 0;
  92	read_lock(&resource_lock);
  93	for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
  94		;
  95	return p;
  96}
  97
  98static void r_stop(struct seq_file *m, void *v)
  99	__releases(resource_lock)
 100{
 101	read_unlock(&resource_lock);
 102}
 103
 104static int r_show(struct seq_file *m, void *v)
 105{
 106	struct resource *root = m->private;
 107	struct resource *r = v, *p;
 108	unsigned long long start, end;
 109	int width = root->end < 0x10000 ? 4 : 8;
 110	int depth;
 111
 112	for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
 113		if (p->parent == root)
 114			break;
 115
 116	if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
 117		start = r->start;
 118		end = r->end;
 119	} else {
 120		start = end = 0;
 121	}
 122
 123	seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
 124			depth * 2, "",
 125			width, start,
 126			width, end,
 127			r->name ? r->name : "<BAD>");
 128	return 0;
 129}
 130
 131static const struct seq_operations resource_op = {
 132	.start	= r_start,
 133	.next	= r_next,
 134	.stop	= r_stop,
 135	.show	= r_show,
 136};
 137
 138static int ioports_open(struct inode *inode, struct file *file)
 139{
 140	int res = seq_open(file, &resource_op);
 141	if (!res) {
 142		struct seq_file *m = file->private_data;
 143		m->private = &ioport_resource;
 144	}
 145	return res;
 146}
 147
 148static int iomem_open(struct inode *inode, struct file *file)
 149{
 150	int res = seq_open(file, &resource_op);
 151	if (!res) {
 152		struct seq_file *m = file->private_data;
 153		m->private = &iomem_resource;
 154	}
 155	return res;
 156}
 157
 158static const struct file_operations proc_ioports_operations = {
 159	.open		= ioports_open,
 160	.read		= seq_read,
 161	.llseek		= seq_lseek,
 162	.release	= seq_release,
 163};
 164
 165static const struct file_operations proc_iomem_operations = {
 166	.open		= iomem_open,
 167	.read		= seq_read,
 168	.llseek		= seq_lseek,
 169	.release	= seq_release,
 170};
 171
 172static int __init ioresources_init(void)
 173{
 174	proc_create("ioports", 0, NULL, &proc_ioports_operations);
 175	proc_create("iomem", 0, NULL, &proc_iomem_operations);
 176	return 0;
 177}
 178__initcall(ioresources_init);
 179
 180#endif /* CONFIG_PROC_FS */
 181
 182static void free_resource(struct resource *res)
 183{
 184	if (!res)
 185		return;
 186
 187	if (!PageSlab(virt_to_head_page(res))) {
 188		spin_lock(&bootmem_resource_lock);
 189		res->sibling = bootmem_resource_free;
 190		bootmem_resource_free = res;
 191		spin_unlock(&bootmem_resource_lock);
 192	} else {
 193		kfree(res);
 194	}
 195}
 196
 197static struct resource *alloc_resource(gfp_t flags)
 198{
 199	struct resource *res = NULL;
 200
 201	spin_lock(&bootmem_resource_lock);
 202	if (bootmem_resource_free) {
 203		res = bootmem_resource_free;
 204		bootmem_resource_free = res->sibling;
 205	}
 206	spin_unlock(&bootmem_resource_lock);
 207
 208	if (res)
 209		memset(res, 0, sizeof(struct resource));
 210	else
 211		res = kzalloc(sizeof(struct resource), flags);
 212
 213	return res;
 214}
 215
 216/* Return the conflict entry if you can't request it */
 217static struct resource * __request_resource(struct resource *root, struct resource *new)
 218{
 219	resource_size_t start = new->start;
 220	resource_size_t end = new->end;
 221	struct resource *tmp, **p;
 222
 223	if (end < start)
 224		return root;
 225	if (start < root->start)
 226		return root;
 227	if (end > root->end)
 228		return root;
 229	p = &root->child;
 230	for (;;) {
 231		tmp = *p;
 232		if (!tmp || tmp->start > end) {
 233			new->sibling = tmp;
 234			*p = new;
 235			new->parent = root;
 236			return NULL;
 237		}
 238		p = &tmp->sibling;
 239		if (tmp->end < start)
 240			continue;
 241		return tmp;
 242	}
 243}
 244
 245static int __release_resource(struct resource *old, bool release_child)
 246{
 247	struct resource *tmp, **p, *chd;
 248
 249	p = &old->parent->child;
 250	for (;;) {
 251		tmp = *p;
 252		if (!tmp)
 253			break;
 254		if (tmp == old) {
 255			if (release_child || !(tmp->child)) {
 256				*p = tmp->sibling;
 257			} else {
 258				for (chd = tmp->child;; chd = chd->sibling) {
 259					chd->parent = tmp->parent;
 260					if (!(chd->sibling))
 261						break;
 262				}
 263				*p = tmp->child;
 264				chd->sibling = tmp->sibling;
 265			}
 266			old->parent = NULL;
 267			return 0;
 268		}
 269		p = &tmp->sibling;
 270	}
 271	return -EINVAL;
 272}
 273
 274static void __release_child_resources(struct resource *r)
 275{
 276	struct resource *tmp, *p;
 277	resource_size_t size;
 278
 279	p = r->child;
 280	r->child = NULL;
 281	while (p) {
 282		tmp = p;
 283		p = p->sibling;
 284
 285		tmp->parent = NULL;
 286		tmp->sibling = NULL;
 287		__release_child_resources(tmp);
 288
 289		printk(KERN_DEBUG "release child resource %pR\n", tmp);
 290		/* need to restore size, and keep flags */
 291		size = resource_size(tmp);
 292		tmp->start = 0;
 293		tmp->end = size - 1;
 294	}
 295}
 296
 297void release_child_resources(struct resource *r)
 298{
 299	write_lock(&resource_lock);
 300	__release_child_resources(r);
 301	write_unlock(&resource_lock);
 302}
 303
 304/**
 305 * request_resource_conflict - request and reserve an I/O or memory resource
 306 * @root: root resource descriptor
 307 * @new: resource descriptor desired by caller
 308 *
 309 * Returns 0 for success, conflict resource on error.
 310 */
 311struct resource *request_resource_conflict(struct resource *root, struct resource *new)
 312{
 313	struct resource *conflict;
 314
 315	write_lock(&resource_lock);
 316	conflict = __request_resource(root, new);
 317	write_unlock(&resource_lock);
 318	return conflict;
 319}
 320
 321/**
 322 * request_resource - request and reserve an I/O or memory resource
 323 * @root: root resource descriptor
 324 * @new: resource descriptor desired by caller
 325 *
 326 * Returns 0 for success, negative error code on error.
 327 */
 328int request_resource(struct resource *root, struct resource *new)
 329{
 330	struct resource *conflict;
 331
 332	conflict = request_resource_conflict(root, new);
 333	return conflict ? -EBUSY : 0;
 334}
 335
 336EXPORT_SYMBOL(request_resource);
 337
 338/**
 339 * release_resource - release a previously reserved resource
 340 * @old: resource pointer
 341 */
 342int release_resource(struct resource *old)
 343{
 344	int retval;
 345
 346	write_lock(&resource_lock);
 347	retval = __release_resource(old, true);
 348	write_unlock(&resource_lock);
 349	return retval;
 350}
 351
 352EXPORT_SYMBOL(release_resource);
 353
 354/*
 355 * Finds the lowest iomem resource existing within [res->start.res->end).
 356 * The caller must specify res->start, res->end, res->flags, and optionally
 357 * desc.  If found, returns 0, res is overwritten, if not found, returns -1.
 358 * This function walks the whole tree and not just first level children until
 359 * and unless first_level_children_only is true.
 360 */
 361static int find_next_iomem_res(struct resource *res, unsigned long desc,
 362			       bool first_level_children_only)
 363{
 364	resource_size_t start, end;
 365	struct resource *p;
 366	bool sibling_only = false;
 367
 368	BUG_ON(!res);
 369
 370	start = res->start;
 371	end = res->end;
 372	BUG_ON(start >= end);
 373
 374	if (first_level_children_only)
 375		sibling_only = true;
 376
 377	read_lock(&resource_lock);
 378
 379	for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
 380		if ((p->flags & res->flags) != res->flags)
 381			continue;
 382		if ((desc != IORES_DESC_NONE) && (desc != p->desc))
 383			continue;
 384		if (p->start > end) {
 385			p = NULL;
 386			break;
 387		}
 388		if ((p->end >= start) && (p->start < end))
 389			break;
 390	}
 391
 392	read_unlock(&resource_lock);
 393	if (!p)
 394		return -1;
 395	/* copy data */
 396	if (res->start < p->start)
 397		res->start = p->start;
 398	if (res->end > p->end)
 399		res->end = p->end;
 400	res->flags = p->flags;
 401	res->desc = p->desc;
 402	return 0;
 403}
 404
 405static int __walk_iomem_res_desc(struct resource *res, unsigned long desc,
 406				 bool first_level_children_only,
 407				 void *arg,
 408				 int (*func)(struct resource *, void *))
 409{
 410	u64 orig_end = res->end;
 411	int ret = -1;
 412
 413	while ((res->start < res->end) &&
 414	       !find_next_iomem_res(res, desc, first_level_children_only)) {
 415		ret = (*func)(res, arg);
 416		if (ret)
 417			break;
 418
 419		res->start = res->end + 1;
 420		res->end = orig_end;
 421	}
 422
 423	return ret;
 424}
 425
 426/*
 427 * Walks through iomem resources and calls func() with matching resource
 428 * ranges. This walks through whole tree and not just first level children.
 429 * All the memory ranges which overlap start,end and also match flags and
 430 * desc are valid candidates.
 431 *
 432 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
 433 * @flags: I/O resource flags
 434 * @start: start addr
 435 * @end: end addr
 436 *
 437 * NOTE: For a new descriptor search, define a new IORES_DESC in
 438 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
 439 */
 440int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
 441		u64 end, void *arg, int (*func)(struct resource *, void *))
 442{
 443	struct resource res;
 
 
 444
 445	res.start = start;
 446	res.end = end;
 447	res.flags = flags;
 
 
 
 
 448
 449	return __walk_iomem_res_desc(&res, desc, false, arg, func);
 
 
 
 
 
 
 
 
 450}
 451
 452/*
 453 * This function calls the @func callback against all memory ranges of type
 454 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
 455 * Now, this function is only for System RAM, it deals with full ranges and
 456 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
 457 * ranges.
 458 */
 459int walk_system_ram_res(u64 start, u64 end, void *arg,
 460				int (*func)(struct resource *, void *))
 461{
 462	struct resource res;
 
 
 463
 464	res.start = start;
 465	res.end = end;
 466	res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 467
 468	return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true,
 469				     arg, func);
 470}
 471
 472/*
 473 * This function calls the @func callback against all memory ranges, which
 474 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
 475 */
 476int walk_mem_res(u64 start, u64 end, void *arg,
 477		 int (*func)(struct resource *, void *))
 478{
 479	struct resource res;
 480
 481	res.start = start;
 482	res.end = end;
 483	res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 484
 485	return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true,
 486				     arg, func);
 487}
 488
 489#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 490
 491/*
 492 * This function calls the @func callback against all memory ranges of type
 493 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
 494 * It is to be used only for System RAM.
 495 */
 496int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 497		void *arg, int (*func)(unsigned long, unsigned long, void *))
 498{
 499	struct resource res;
 500	unsigned long pfn, end_pfn;
 501	u64 orig_end;
 502	int ret = -1;
 503
 504	res.start = (u64) start_pfn << PAGE_SHIFT;
 505	res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 506	res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 507	orig_end = res.end;
 508	while ((res.start < res.end) &&
 509		(find_next_iomem_res(&res, IORES_DESC_NONE, true) >= 0)) {
 510		pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 511		end_pfn = (res.end + 1) >> PAGE_SHIFT;
 512		if (end_pfn > pfn)
 513			ret = (*func)(pfn, end_pfn - pfn, arg);
 514		if (ret)
 515			break;
 516		res.start = res.end + 1;
 517		res.end = orig_end;
 518	}
 519	return ret;
 520}
 521
 522#endif
 523
 524static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
 525{
 526	return 1;
 527}
 528
 529/*
 530 * This generic page_is_ram() returns true if specified address is
 531 * registered as System RAM in iomem_resource list.
 532 */
 533int __weak page_is_ram(unsigned long pfn)
 534{
 535	return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
 536}
 537EXPORT_SYMBOL_GPL(page_is_ram);
 538
 539/**
 540 * region_intersects() - determine intersection of region with known resources
 541 * @start: region start address
 542 * @size: size of region
 543 * @flags: flags of resource (in iomem_resource)
 544 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
 545 *
 546 * Check if the specified region partially overlaps or fully eclipses a
 547 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
 548 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
 549 * return REGION_MIXED if the region overlaps @flags/@desc and another
 550 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
 551 * and no other defined resource. Note that REGION_INTERSECTS is also
 552 * returned in the case when the specified region overlaps RAM and undefined
 553 * memory holes.
 554 *
 555 * region_intersect() is used by memory remapping functions to ensure
 556 * the user is not remapping RAM and is a vast speed up over walking
 557 * through the resource table page by page.
 558 */
 559int region_intersects(resource_size_t start, size_t size, unsigned long flags,
 560		      unsigned long desc)
 561{
 562	resource_size_t end = start + size - 1;
 563	int type = 0; int other = 0;
 564	struct resource *p;
 565
 566	read_lock(&resource_lock);
 567	for (p = iomem_resource.child; p ; p = p->sibling) {
 568		bool is_type = (((p->flags & flags) == flags) &&
 569				((desc == IORES_DESC_NONE) ||
 570				 (desc == p->desc)));
 571
 572		if (start >= p->start && start <= p->end)
 573			is_type ? type++ : other++;
 574		if (end >= p->start && end <= p->end)
 575			is_type ? type++ : other++;
 576		if (p->start >= start && p->end <= end)
 577			is_type ? type++ : other++;
 578	}
 579	read_unlock(&resource_lock);
 580
 581	if (other == 0)
 582		return type ? REGION_INTERSECTS : REGION_DISJOINT;
 583
 584	if (type)
 585		return REGION_MIXED;
 586
 587	return REGION_DISJOINT;
 588}
 589EXPORT_SYMBOL_GPL(region_intersects);
 590
 591void __weak arch_remove_reservations(struct resource *avail)
 592{
 593}
 594
 595static resource_size_t simple_align_resource(void *data,
 596					     const struct resource *avail,
 597					     resource_size_t size,
 598					     resource_size_t align)
 599{
 600	return avail->start;
 601}
 602
 603static void resource_clip(struct resource *res, resource_size_t min,
 604			  resource_size_t max)
 605{
 606	if (res->start < min)
 607		res->start = min;
 608	if (res->end > max)
 609		res->end = max;
 610}
 611
 612/*
 613 * Find empty slot in the resource tree with the given range and
 614 * alignment constraints
 615 */
 616static int __find_resource(struct resource *root, struct resource *old,
 617			 struct resource *new,
 618			 resource_size_t  size,
 619			 struct resource_constraint *constraint)
 620{
 621	struct resource *this = root->child;
 622	struct resource tmp = *new, avail, alloc;
 623
 624	tmp.start = root->start;
 625	/*
 626	 * Skip past an allocated resource that starts at 0, since the assignment
 627	 * of this->start - 1 to tmp->end below would cause an underflow.
 628	 */
 629	if (this && this->start == root->start) {
 630		tmp.start = (this == old) ? old->start : this->end + 1;
 631		this = this->sibling;
 632	}
 633	for(;;) {
 634		if (this)
 635			tmp.end = (this == old) ?  this->end : this->start - 1;
 636		else
 637			tmp.end = root->end;
 638
 639		if (tmp.end < tmp.start)
 640			goto next;
 641
 642		resource_clip(&tmp, constraint->min, constraint->max);
 643		arch_remove_reservations(&tmp);
 644
 645		/* Check for overflow after ALIGN() */
 646		avail.start = ALIGN(tmp.start, constraint->align);
 647		avail.end = tmp.end;
 648		avail.flags = new->flags & ~IORESOURCE_UNSET;
 649		if (avail.start >= tmp.start) {
 650			alloc.flags = avail.flags;
 651			alloc.start = constraint->alignf(constraint->alignf_data, &avail,
 652					size, constraint->align);
 653			alloc.end = alloc.start + size - 1;
 654			if (alloc.start <= alloc.end &&
 655			    resource_contains(&avail, &alloc)) {
 656				new->start = alloc.start;
 657				new->end = alloc.end;
 658				return 0;
 659			}
 660		}
 661
 662next:		if (!this || this->end == root->end)
 663			break;
 664
 665		if (this != old)
 666			tmp.start = this->end + 1;
 667		this = this->sibling;
 668	}
 669	return -EBUSY;
 670}
 671
 672/*
 673 * Find empty slot in the resource tree given range and alignment.
 674 */
 675static int find_resource(struct resource *root, struct resource *new,
 676			resource_size_t size,
 677			struct resource_constraint  *constraint)
 678{
 679	return  __find_resource(root, NULL, new, size, constraint);
 680}
 681
 682/**
 683 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
 684 *	The resource will be relocated if the new size cannot be reallocated in the
 685 *	current location.
 686 *
 687 * @root: root resource descriptor
 688 * @old:  resource descriptor desired by caller
 689 * @newsize: new size of the resource descriptor
 690 * @constraint: the size and alignment constraints to be met.
 691 */
 692static int reallocate_resource(struct resource *root, struct resource *old,
 693			resource_size_t newsize,
 694			struct resource_constraint  *constraint)
 695{
 696	int err=0;
 697	struct resource new = *old;
 698	struct resource *conflict;
 699
 700	write_lock(&resource_lock);
 701
 702	if ((err = __find_resource(root, old, &new, newsize, constraint)))
 703		goto out;
 704
 705	if (resource_contains(&new, old)) {
 706		old->start = new.start;
 707		old->end = new.end;
 708		goto out;
 709	}
 710
 711	if (old->child) {
 712		err = -EBUSY;
 713		goto out;
 714	}
 715
 716	if (resource_contains(old, &new)) {
 717		old->start = new.start;
 718		old->end = new.end;
 719	} else {
 720		__release_resource(old, true);
 721		*old = new;
 722		conflict = __request_resource(root, old);
 723		BUG_ON(conflict);
 724	}
 725out:
 726	write_unlock(&resource_lock);
 727	return err;
 728}
 729
 730
 731/**
 732 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
 733 * 	The resource will be reallocated with a new size if it was already allocated
 734 * @root: root resource descriptor
 735 * @new: resource descriptor desired by caller
 736 * @size: requested resource region size
 737 * @min: minimum boundary to allocate
 738 * @max: maximum boundary to allocate
 739 * @align: alignment requested, in bytes
 740 * @alignf: alignment function, optional, called if not NULL
 741 * @alignf_data: arbitrary data to pass to the @alignf function
 742 */
 743int allocate_resource(struct resource *root, struct resource *new,
 744		      resource_size_t size, resource_size_t min,
 745		      resource_size_t max, resource_size_t align,
 746		      resource_size_t (*alignf)(void *,
 747						const struct resource *,
 748						resource_size_t,
 749						resource_size_t),
 750		      void *alignf_data)
 751{
 752	int err;
 753	struct resource_constraint constraint;
 754
 755	if (!alignf)
 756		alignf = simple_align_resource;
 757
 758	constraint.min = min;
 759	constraint.max = max;
 760	constraint.align = align;
 761	constraint.alignf = alignf;
 762	constraint.alignf_data = alignf_data;
 763
 764	if ( new->parent ) {
 765		/* resource is already allocated, try reallocating with
 766		   the new constraints */
 767		return reallocate_resource(root, new, size, &constraint);
 768	}
 769
 770	write_lock(&resource_lock);
 771	err = find_resource(root, new, size, &constraint);
 772	if (err >= 0 && __request_resource(root, new))
 773		err = -EBUSY;
 774	write_unlock(&resource_lock);
 775	return err;
 776}
 777
 778EXPORT_SYMBOL(allocate_resource);
 779
 780/**
 781 * lookup_resource - find an existing resource by a resource start address
 782 * @root: root resource descriptor
 783 * @start: resource start address
 784 *
 785 * Returns a pointer to the resource if found, NULL otherwise
 786 */
 787struct resource *lookup_resource(struct resource *root, resource_size_t start)
 788{
 789	struct resource *res;
 790
 791	read_lock(&resource_lock);
 792	for (res = root->child; res; res = res->sibling) {
 793		if (res->start == start)
 794			break;
 795	}
 796	read_unlock(&resource_lock);
 797
 798	return res;
 799}
 800
 801/*
 802 * Insert a resource into the resource tree. If successful, return NULL,
 803 * otherwise return the conflicting resource (compare to __request_resource())
 804 */
 805static struct resource * __insert_resource(struct resource *parent, struct resource *new)
 806{
 807	struct resource *first, *next;
 808
 809	for (;; parent = first) {
 810		first = __request_resource(parent, new);
 811		if (!first)
 812			return first;
 813
 814		if (first == parent)
 815			return first;
 816		if (WARN_ON(first == new))	/* duplicated insertion */
 817			return first;
 818
 819		if ((first->start > new->start) || (first->end < new->end))
 820			break;
 821		if ((first->start == new->start) && (first->end == new->end))
 822			break;
 823	}
 824
 825	for (next = first; ; next = next->sibling) {
 826		/* Partial overlap? Bad, and unfixable */
 827		if (next->start < new->start || next->end > new->end)
 828			return next;
 829		if (!next->sibling)
 830			break;
 831		if (next->sibling->start > new->end)
 832			break;
 833	}
 834
 835	new->parent = parent;
 836	new->sibling = next->sibling;
 837	new->child = first;
 838
 839	next->sibling = NULL;
 840	for (next = first; next; next = next->sibling)
 841		next->parent = new;
 842
 843	if (parent->child == first) {
 844		parent->child = new;
 845	} else {
 846		next = parent->child;
 847		while (next->sibling != first)
 848			next = next->sibling;
 849		next->sibling = new;
 850	}
 851	return NULL;
 852}
 853
 854/**
 855 * insert_resource_conflict - Inserts resource in the resource tree
 856 * @parent: parent of the new resource
 857 * @new: new resource to insert
 858 *
 859 * Returns 0 on success, conflict resource if the resource can't be inserted.
 860 *
 861 * This function is equivalent to request_resource_conflict when no conflict
 862 * happens. If a conflict happens, and the conflicting resources
 863 * entirely fit within the range of the new resource, then the new
 864 * resource is inserted and the conflicting resources become children of
 865 * the new resource.
 866 *
 867 * This function is intended for producers of resources, such as FW modules
 868 * and bus drivers.
 869 */
 870struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
 871{
 872	struct resource *conflict;
 873
 874	write_lock(&resource_lock);
 875	conflict = __insert_resource(parent, new);
 876	write_unlock(&resource_lock);
 877	return conflict;
 878}
 879
 880/**
 881 * insert_resource - Inserts a resource in the resource tree
 882 * @parent: parent of the new resource
 883 * @new: new resource to insert
 884 *
 885 * Returns 0 on success, -EBUSY if the resource can't be inserted.
 886 *
 887 * This function is intended for producers of resources, such as FW modules
 888 * and bus drivers.
 889 */
 890int insert_resource(struct resource *parent, struct resource *new)
 891{
 892	struct resource *conflict;
 893
 894	conflict = insert_resource_conflict(parent, new);
 895	return conflict ? -EBUSY : 0;
 896}
 897EXPORT_SYMBOL_GPL(insert_resource);
 898
 899/**
 900 * insert_resource_expand_to_fit - Insert a resource into the resource tree
 901 * @root: root resource descriptor
 902 * @new: new resource to insert
 903 *
 904 * Insert a resource into the resource tree, possibly expanding it in order
 905 * to make it encompass any conflicting resources.
 906 */
 907void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 908{
 909	if (new->parent)
 910		return;
 911
 912	write_lock(&resource_lock);
 913	for (;;) {
 914		struct resource *conflict;
 915
 916		conflict = __insert_resource(root, new);
 917		if (!conflict)
 918			break;
 919		if (conflict == root)
 920			break;
 921
 922		/* Ok, expand resource to cover the conflict, then try again .. */
 923		if (conflict->start < new->start)
 924			new->start = conflict->start;
 925		if (conflict->end > new->end)
 926			new->end = conflict->end;
 927
 928		printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
 929	}
 930	write_unlock(&resource_lock);
 931}
 932
 933/**
 934 * remove_resource - Remove a resource in the resource tree
 935 * @old: resource to remove
 936 *
 937 * Returns 0 on success, -EINVAL if the resource is not valid.
 938 *
 939 * This function removes a resource previously inserted by insert_resource()
 940 * or insert_resource_conflict(), and moves the children (if any) up to
 941 * where they were before.  insert_resource() and insert_resource_conflict()
 942 * insert a new resource, and move any conflicting resources down to the
 943 * children of the new resource.
 944 *
 945 * insert_resource(), insert_resource_conflict() and remove_resource() are
 946 * intended for producers of resources, such as FW modules and bus drivers.
 947 */
 948int remove_resource(struct resource *old)
 949{
 950	int retval;
 951
 952	write_lock(&resource_lock);
 953	retval = __release_resource(old, false);
 954	write_unlock(&resource_lock);
 955	return retval;
 956}
 957EXPORT_SYMBOL_GPL(remove_resource);
 958
 959static int __adjust_resource(struct resource *res, resource_size_t start,
 960				resource_size_t size)
 961{
 962	struct resource *tmp, *parent = res->parent;
 963	resource_size_t end = start + size - 1;
 964	int result = -EBUSY;
 965
 966	if (!parent)
 967		goto skip;
 968
 969	if ((start < parent->start) || (end > parent->end))
 970		goto out;
 971
 972	if (res->sibling && (res->sibling->start <= end))
 973		goto out;
 974
 975	tmp = parent->child;
 976	if (tmp != res) {
 977		while (tmp->sibling != res)
 978			tmp = tmp->sibling;
 979		if (start <= tmp->end)
 980			goto out;
 981	}
 982
 983skip:
 984	for (tmp = res->child; tmp; tmp = tmp->sibling)
 985		if ((tmp->start < start) || (tmp->end > end))
 986			goto out;
 987
 988	res->start = start;
 989	res->end = end;
 990	result = 0;
 991
 992 out:
 993	return result;
 994}
 995
 996/**
 997 * adjust_resource - modify a resource's start and size
 998 * @res: resource to modify
 999 * @start: new start value
1000 * @size: new size
1001 *
1002 * Given an existing resource, change its start and size to match the
1003 * arguments.  Returns 0 on success, -EBUSY if it can't fit.
1004 * Existing children of the resource are assumed to be immutable.
1005 */
1006int adjust_resource(struct resource *res, resource_size_t start,
1007			resource_size_t size)
1008{
1009	int result;
1010
1011	write_lock(&resource_lock);
1012	result = __adjust_resource(res, start, size);
1013	write_unlock(&resource_lock);
1014	return result;
1015}
1016EXPORT_SYMBOL(adjust_resource);
1017
1018static void __init __reserve_region_with_split(struct resource *root,
1019		resource_size_t start, resource_size_t end,
1020		const char *name)
1021{
1022	struct resource *parent = root;
1023	struct resource *conflict;
1024	struct resource *res = alloc_resource(GFP_ATOMIC);
1025	struct resource *next_res = NULL;
1026	int type = resource_type(root);
1027
1028	if (!res)
1029		return;
1030
1031	res->name = name;
1032	res->start = start;
1033	res->end = end;
1034	res->flags = type | IORESOURCE_BUSY;
1035	res->desc = IORES_DESC_NONE;
1036
1037	while (1) {
1038
1039		conflict = __request_resource(parent, res);
1040		if (!conflict) {
1041			if (!next_res)
1042				break;
1043			res = next_res;
1044			next_res = NULL;
1045			continue;
1046		}
1047
1048		/* conflict covered whole area */
1049		if (conflict->start <= res->start &&
1050				conflict->end >= res->end) {
1051			free_resource(res);
1052			WARN_ON(next_res);
1053			break;
1054		}
1055
1056		/* failed, split and try again */
1057		if (conflict->start > res->start) {
1058			end = res->end;
1059			res->end = conflict->start - 1;
1060			if (conflict->end < end) {
1061				next_res = alloc_resource(GFP_ATOMIC);
1062				if (!next_res) {
1063					free_resource(res);
1064					break;
1065				}
1066				next_res->name = name;
1067				next_res->start = conflict->end + 1;
1068				next_res->end = end;
1069				next_res->flags = type | IORESOURCE_BUSY;
1070				next_res->desc = IORES_DESC_NONE;
1071			}
1072		} else {
1073			res->start = conflict->end + 1;
1074		}
1075	}
1076
1077}
1078
1079void __init reserve_region_with_split(struct resource *root,
1080		resource_size_t start, resource_size_t end,
1081		const char *name)
1082{
1083	int abort = 0;
1084
1085	write_lock(&resource_lock);
1086	if (root->start > start || root->end < end) {
1087		pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1088		       (unsigned long long)start, (unsigned long long)end,
1089		       root);
1090		if (start > root->end || end < root->start)
1091			abort = 1;
1092		else {
1093			if (end > root->end)
1094				end = root->end;
1095			if (start < root->start)
1096				start = root->start;
1097			pr_err("fixing request to [0x%llx-0x%llx]\n",
1098			       (unsigned long long)start,
1099			       (unsigned long long)end);
1100		}
1101		dump_stack();
1102	}
1103	if (!abort)
1104		__reserve_region_with_split(root, start, end, name);
1105	write_unlock(&resource_lock);
1106}
1107
1108/**
1109 * resource_alignment - calculate resource's alignment
1110 * @res: resource pointer
1111 *
1112 * Returns alignment on success, 0 (invalid alignment) on failure.
1113 */
1114resource_size_t resource_alignment(struct resource *res)
1115{
1116	switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1117	case IORESOURCE_SIZEALIGN:
1118		return resource_size(res);
1119	case IORESOURCE_STARTALIGN:
1120		return res->start;
1121	default:
1122		return 0;
1123	}
1124}
1125
1126/*
1127 * This is compatibility stuff for IO resources.
1128 *
1129 * Note how this, unlike the above, knows about
1130 * the IO flag meanings (busy etc).
1131 *
1132 * request_region creates a new busy region.
1133 *
1134 * release_region releases a matching busy region.
1135 */
1136
1137static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1138
1139/**
1140 * __request_region - create a new busy resource region
1141 * @parent: parent resource descriptor
1142 * @start: resource start address
1143 * @n: resource region size
1144 * @name: reserving caller's ID string
1145 * @flags: IO resource flags
1146 */
1147struct resource * __request_region(struct resource *parent,
1148				   resource_size_t start, resource_size_t n,
1149				   const char *name, int flags)
1150{
1151	DECLARE_WAITQUEUE(wait, current);
1152	struct resource *res = alloc_resource(GFP_KERNEL);
1153
1154	if (!res)
1155		return NULL;
1156
1157	res->name = name;
1158	res->start = start;
1159	res->end = start + n - 1;
1160
1161	write_lock(&resource_lock);
1162
1163	for (;;) {
1164		struct resource *conflict;
1165
1166		res->flags = resource_type(parent) | resource_ext_type(parent);
1167		res->flags |= IORESOURCE_BUSY | flags;
1168		res->desc = parent->desc;
1169
1170		conflict = __request_resource(parent, res);
1171		if (!conflict)
1172			break;
1173		if (conflict != parent) {
1174			if (!(conflict->flags & IORESOURCE_BUSY)) {
1175				parent = conflict;
1176				continue;
1177			}
1178		}
1179		if (conflict->flags & flags & IORESOURCE_MUXED) {
1180			add_wait_queue(&muxed_resource_wait, &wait);
1181			write_unlock(&resource_lock);
1182			set_current_state(TASK_UNINTERRUPTIBLE);
1183			schedule();
1184			remove_wait_queue(&muxed_resource_wait, &wait);
1185			write_lock(&resource_lock);
1186			continue;
1187		}
1188		/* Uhhuh, that didn't work out.. */
1189		free_resource(res);
1190		res = NULL;
1191		break;
1192	}
1193	write_unlock(&resource_lock);
1194	return res;
1195}
1196EXPORT_SYMBOL(__request_region);
1197
1198/**
1199 * __release_region - release a previously reserved resource region
1200 * @parent: parent resource descriptor
1201 * @start: resource start address
1202 * @n: resource region size
1203 *
1204 * The described resource region must match a currently busy region.
1205 */
1206void __release_region(struct resource *parent, resource_size_t start,
1207			resource_size_t n)
1208{
1209	struct resource **p;
1210	resource_size_t end;
1211
1212	p = &parent->child;
1213	end = start + n - 1;
1214
1215	write_lock(&resource_lock);
1216
1217	for (;;) {
1218		struct resource *res = *p;
1219
1220		if (!res)
1221			break;
1222		if (res->start <= start && res->end >= end) {
1223			if (!(res->flags & IORESOURCE_BUSY)) {
1224				p = &res->child;
1225				continue;
1226			}
1227			if (res->start != start || res->end != end)
1228				break;
1229			*p = res->sibling;
1230			write_unlock(&resource_lock);
1231			if (res->flags & IORESOURCE_MUXED)
1232				wake_up(&muxed_resource_wait);
1233			free_resource(res);
1234			return;
1235		}
1236		p = &res->sibling;
1237	}
1238
1239	write_unlock(&resource_lock);
1240
1241	printk(KERN_WARNING "Trying to free nonexistent resource "
1242		"<%016llx-%016llx>\n", (unsigned long long)start,
1243		(unsigned long long)end);
1244}
1245EXPORT_SYMBOL(__release_region);
1246
1247#ifdef CONFIG_MEMORY_HOTREMOVE
1248/**
1249 * release_mem_region_adjustable - release a previously reserved memory region
1250 * @parent: parent resource descriptor
1251 * @start: resource start address
1252 * @size: resource region size
1253 *
1254 * This interface is intended for memory hot-delete.  The requested region
1255 * is released from a currently busy memory resource.  The requested region
1256 * must either match exactly or fit into a single busy resource entry.  In
1257 * the latter case, the remaining resource is adjusted accordingly.
1258 * Existing children of the busy memory resource must be immutable in the
1259 * request.
1260 *
1261 * Note:
1262 * - Additional release conditions, such as overlapping region, can be
1263 *   supported after they are confirmed as valid cases.
1264 * - When a busy memory resource gets split into two entries, the code
1265 *   assumes that all children remain in the lower address entry for
1266 *   simplicity.  Enhance this logic when necessary.
1267 */
1268int release_mem_region_adjustable(struct resource *parent,
1269			resource_size_t start, resource_size_t size)
1270{
1271	struct resource **p;
1272	struct resource *res;
1273	struct resource *new_res;
1274	resource_size_t end;
1275	int ret = -EINVAL;
1276
1277	end = start + size - 1;
1278	if ((start < parent->start) || (end > parent->end))
1279		return ret;
1280
1281	/* The alloc_resource() result gets checked later */
1282	new_res = alloc_resource(GFP_KERNEL);
1283
1284	p = &parent->child;
1285	write_lock(&resource_lock);
1286
1287	while ((res = *p)) {
1288		if (res->start >= end)
1289			break;
1290
1291		/* look for the next resource if it does not fit into */
1292		if (res->start > start || res->end < end) {
1293			p = &res->sibling;
1294			continue;
1295		}
1296
1297		if (!(res->flags & IORESOURCE_MEM))
1298			break;
1299
1300		if (!(res->flags & IORESOURCE_BUSY)) {
1301			p = &res->child;
1302			continue;
1303		}
1304
1305		/* found the target resource; let's adjust accordingly */
1306		if (res->start == start && res->end == end) {
1307			/* free the whole entry */
1308			*p = res->sibling;
1309			free_resource(res);
1310			ret = 0;
1311		} else if (res->start == start && res->end != end) {
1312			/* adjust the start */
1313			ret = __adjust_resource(res, end + 1,
1314						res->end - end);
1315		} else if (res->start != start && res->end == end) {
1316			/* adjust the end */
1317			ret = __adjust_resource(res, res->start,
1318						start - res->start);
1319		} else {
1320			/* split into two entries */
1321			if (!new_res) {
1322				ret = -ENOMEM;
1323				break;
1324			}
1325			new_res->name = res->name;
1326			new_res->start = end + 1;
1327			new_res->end = res->end;
1328			new_res->flags = res->flags;
1329			new_res->desc = res->desc;
1330			new_res->parent = res->parent;
1331			new_res->sibling = res->sibling;
1332			new_res->child = NULL;
1333
1334			ret = __adjust_resource(res, res->start,
1335						start - res->start);
1336			if (ret)
1337				break;
1338			res->sibling = new_res;
1339			new_res = NULL;
1340		}
1341
1342		break;
1343	}
1344
1345	write_unlock(&resource_lock);
1346	free_resource(new_res);
1347	return ret;
1348}
1349#endif	/* CONFIG_MEMORY_HOTREMOVE */
1350
1351/*
1352 * Managed region resource
1353 */
1354static void devm_resource_release(struct device *dev, void *ptr)
1355{
1356	struct resource **r = ptr;
1357
1358	release_resource(*r);
1359}
1360
1361/**
1362 * devm_request_resource() - request and reserve an I/O or memory resource
1363 * @dev: device for which to request the resource
1364 * @root: root of the resource tree from which to request the resource
1365 * @new: descriptor of the resource to request
1366 *
1367 * This is a device-managed version of request_resource(). There is usually
1368 * no need to release resources requested by this function explicitly since
1369 * that will be taken care of when the device is unbound from its driver.
1370 * If for some reason the resource needs to be released explicitly, because
1371 * of ordering issues for example, drivers must call devm_release_resource()
1372 * rather than the regular release_resource().
1373 *
1374 * When a conflict is detected between any existing resources and the newly
1375 * requested resource, an error message will be printed.
1376 *
1377 * Returns 0 on success or a negative error code on failure.
1378 */
1379int devm_request_resource(struct device *dev, struct resource *root,
1380			  struct resource *new)
1381{
1382	struct resource *conflict, **ptr;
1383
1384	ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1385	if (!ptr)
1386		return -ENOMEM;
1387
1388	*ptr = new;
1389
1390	conflict = request_resource_conflict(root, new);
1391	if (conflict) {
1392		dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1393			new, conflict->name, conflict);
1394		devres_free(ptr);
1395		return -EBUSY;
1396	}
1397
1398	devres_add(dev, ptr);
1399	return 0;
1400}
1401EXPORT_SYMBOL(devm_request_resource);
1402
1403static int devm_resource_match(struct device *dev, void *res, void *data)
1404{
1405	struct resource **ptr = res;
1406
1407	return *ptr == data;
1408}
1409
1410/**
1411 * devm_release_resource() - release a previously requested resource
1412 * @dev: device for which to release the resource
1413 * @new: descriptor of the resource to release
1414 *
1415 * Releases a resource previously requested using devm_request_resource().
1416 */
1417void devm_release_resource(struct device *dev, struct resource *new)
1418{
1419	WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1420			       new));
1421}
1422EXPORT_SYMBOL(devm_release_resource);
1423
1424struct region_devres {
1425	struct resource *parent;
1426	resource_size_t start;
1427	resource_size_t n;
1428};
1429
1430static void devm_region_release(struct device *dev, void *res)
1431{
1432	struct region_devres *this = res;
1433
1434	__release_region(this->parent, this->start, this->n);
1435}
1436
1437static int devm_region_match(struct device *dev, void *res, void *match_data)
1438{
1439	struct region_devres *this = res, *match = match_data;
1440
1441	return this->parent == match->parent &&
1442		this->start == match->start && this->n == match->n;
1443}
1444
1445struct resource * __devm_request_region(struct device *dev,
1446				struct resource *parent, resource_size_t start,
1447				resource_size_t n, const char *name)
1448{
1449	struct region_devres *dr = NULL;
1450	struct resource *res;
1451
1452	dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1453			  GFP_KERNEL);
1454	if (!dr)
1455		return NULL;
1456
1457	dr->parent = parent;
1458	dr->start = start;
1459	dr->n = n;
1460
1461	res = __request_region(parent, start, n, name, 0);
1462	if (res)
1463		devres_add(dev, dr);
1464	else
1465		devres_free(dr);
1466
1467	return res;
1468}
1469EXPORT_SYMBOL(__devm_request_region);
1470
1471void __devm_release_region(struct device *dev, struct resource *parent,
1472			   resource_size_t start, resource_size_t n)
1473{
1474	struct region_devres match_data = { parent, start, n };
1475
1476	__release_region(parent, start, n);
1477	WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1478			       &match_data));
1479}
1480EXPORT_SYMBOL(__devm_release_region);
1481
1482/*
1483 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1484 */
1485#define MAXRESERVE 4
1486static int __init reserve_setup(char *str)
1487{
1488	static int reserved;
1489	static struct resource reserve[MAXRESERVE];
1490
1491	for (;;) {
1492		unsigned int io_start, io_num;
1493		int x = reserved;
1494		struct resource *parent;
1495
1496		if (get_option(&str, &io_start) != 2)
1497			break;
1498		if (get_option(&str, &io_num) == 0)
1499			break;
1500		if (x < MAXRESERVE) {
1501			struct resource *res = reserve + x;
1502
1503			/*
1504			 * If the region starts below 0x10000, we assume it's
1505			 * I/O port space; otherwise assume it's memory.
1506			 */
1507			if (io_start < 0x10000) {
1508				res->flags = IORESOURCE_IO;
1509				parent = &ioport_resource;
1510			} else {
1511				res->flags = IORESOURCE_MEM;
1512				parent = &iomem_resource;
1513			}
1514			res->name = "reserved";
1515			res->start = io_start;
1516			res->end = io_start + io_num - 1;
1517			res->flags |= IORESOURCE_BUSY;
1518			res->desc = IORES_DESC_NONE;
1519			res->child = NULL;
1520			if (request_resource(parent, res) == 0)
1521				reserved = x+1;
1522		}
1523	}
1524	return 1;
1525}
 
1526__setup("reserve=", reserve_setup);
1527
1528/*
1529 * Check if the requested addr and size spans more than any slot in the
1530 * iomem resource tree.
1531 */
1532int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1533{
1534	struct resource *p = &iomem_resource;
1535	int err = 0;
1536	loff_t l;
1537
1538	read_lock(&resource_lock);
1539	for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1540		/*
1541		 * We can probably skip the resources without
1542		 * IORESOURCE_IO attribute?
1543		 */
1544		if (p->start >= addr + size)
1545			continue;
1546		if (p->end < addr)
1547			continue;
1548		if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1549		    PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1550			continue;
1551		/*
1552		 * if a resource is "BUSY", it's not a hardware resource
1553		 * but a driver mapping of such a resource; we don't want
1554		 * to warn for those; some drivers legitimately map only
1555		 * partial hardware resources. (example: vesafb)
1556		 */
1557		if (p->flags & IORESOURCE_BUSY)
1558			continue;
1559
1560		printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1561		       (unsigned long long)addr,
1562		       (unsigned long long)(addr + size - 1),
1563		       p->name, p);
1564		err = -1;
1565		break;
1566	}
1567	read_unlock(&resource_lock);
1568
1569	return err;
1570}
1571
1572#ifdef CONFIG_STRICT_DEVMEM
1573static int strict_iomem_checks = 1;
1574#else
1575static int strict_iomem_checks;
1576#endif
1577
1578/*
1579 * check if an address is reserved in the iomem resource tree
1580 * returns true if reserved, false if not reserved.
1581 */
1582bool iomem_is_exclusive(u64 addr)
1583{
1584	struct resource *p = &iomem_resource;
1585	bool err = false;
1586	loff_t l;
1587	int size = PAGE_SIZE;
1588
1589	if (!strict_iomem_checks)
1590		return false;
1591
1592	addr = addr & PAGE_MASK;
1593
1594	read_lock(&resource_lock);
1595	for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1596		/*
1597		 * We can probably skip the resources without
1598		 * IORESOURCE_IO attribute?
1599		 */
1600		if (p->start >= addr + size)
1601			break;
1602		if (p->end < addr)
1603			continue;
1604		/*
1605		 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1606		 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1607		 * resource is busy.
1608		 */
1609		if ((p->flags & IORESOURCE_BUSY) == 0)
1610			continue;
1611		if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1612				|| p->flags & IORESOURCE_EXCLUSIVE) {
1613			err = true;
1614			break;
1615		}
1616	}
1617	read_unlock(&resource_lock);
1618
1619	return err;
1620}
1621
1622struct resource_entry *resource_list_create_entry(struct resource *res,
1623						  size_t extra_size)
1624{
1625	struct resource_entry *entry;
1626
1627	entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1628	if (entry) {
1629		INIT_LIST_HEAD(&entry->node);
1630		entry->res = res ? res : &entry->__res;
1631	}
1632
1633	return entry;
1634}
1635EXPORT_SYMBOL(resource_list_create_entry);
1636
1637void resource_list_free(struct list_head *head)
1638{
1639	struct resource_entry *entry, *tmp;
1640
1641	list_for_each_entry_safe(entry, tmp, head, node)
1642		resource_list_destroy_entry(entry);
1643}
1644EXPORT_SYMBOL(resource_list_free);
1645
1646static int __init strict_iomem(char *str)
1647{
1648	if (strstr(str, "relaxed"))
1649		strict_iomem_checks = 0;
1650	if (strstr(str, "strict"))
1651		strict_iomem_checks = 1;
1652	return 1;
1653}
1654
1655__setup("iomem=", strict_iomem);