1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *	linux/kernel/resource.c
   4 *
   5 * Copyright (C) 1999	Linus Torvalds
   6 * Copyright (C) 1999	Martin Mares <mj@ucw.cz>
   7 *
   8 * Arbitrary resource management.
   9 */
  10
  11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13#include <linux/export.h>
  14#include <linux/errno.h>
  15#include <linux/ioport.h>
  16#include <linux/init.h>
  17#include <linux/slab.h>
  18#include <linux/spinlock.h>
  19#include <linux/fs.h>
  20#include <linux/proc_fs.h>
  21#include <linux/pseudo_fs.h>
  22#include <linux/sched.h>
  23#include <linux/seq_file.h>
  24#include <linux/device.h>
  25#include <linux/pfn.h>
  26#include <linux/mm.h>
  27#include <linux/mount.h>
  28#include <linux/resource_ext.h>
  29#include <uapi/linux/magic.h>
 
 
  30#include <asm/io.h>
  31
  32
  33struct resource ioport_resource = {
  34	.name	= "PCI IO",
  35	.start	= 0,
  36	.end	= IO_SPACE_LIMIT,
  37	.flags	= IORESOURCE_IO,
  38};
  39EXPORT_SYMBOL(ioport_resource);
  40
  41struct resource iomem_resource = {
  42	.name	= "PCI mem",
  43	.start	= 0,
  44	.end	= -1,
  45	.flags	= IORESOURCE_MEM,
  46};
  47EXPORT_SYMBOL(iomem_resource);
  48
  49/* constraints to be met while allocating resources */
  50struct resource_constraint {
  51	resource_size_t min, max, align;
  52	resource_size_t (*alignf)(void *, const struct resource *,
  53			resource_size_t, resource_size_t);
  54	void *alignf_data;
  55};
  56
  57static DEFINE_RWLOCK(resource_lock);
  58
  59/*
  60 * For memory hotplug, there is no way to free resource entries allocated
  61 * by boot mem after the system is up. So for reusing the resource entry
  62 * we need to remember the resource.
  63 */
  64static struct resource *bootmem_resource_free;
  65static DEFINE_SPINLOCK(bootmem_resource_lock);
  66
  67static struct resource *next_resource(struct resource *p)
  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);
  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 = PDE_DATA(file_inode(m->file));
  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 = PDE_DATA(file_inode(m->file));
 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 __init ioresources_init(void)
 139{
 140	proc_create_seq_data("ioports", 0, NULL, &resource_op,
 141			&ioport_resource);
 142	proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource);
 143	return 0;
 144}
 145__initcall(ioresources_init);
 146
 147#endif /* CONFIG_PROC_FS */
 148
 149static void free_resource(struct resource *res)
 150{
 151	if (!res)
 152		return;
 153
 154	if (!PageSlab(virt_to_head_page(res))) {
 155		spin_lock(&bootmem_resource_lock);
 156		res->sibling = bootmem_resource_free;
 157		bootmem_resource_free = res;
 158		spin_unlock(&bootmem_resource_lock);
 159	} else {
 160		kfree(res);
 161	}
 162}
 163
 164static struct resource *alloc_resource(gfp_t flags)
 165{
 166	struct resource *res = NULL;
 167
 168	spin_lock(&bootmem_resource_lock);
 169	if (bootmem_resource_free) {
 170		res = bootmem_resource_free;
 171		bootmem_resource_free = res->sibling;
 172	}
 173	spin_unlock(&bootmem_resource_lock);
 174
 175	if (res)
 176		memset(res, 0, sizeof(struct resource));
 177	else
 178		res = kzalloc(sizeof(struct resource), flags);
 179
 180	return res;
 181}
 182
 183/* Return the conflict entry if you can't request it */
 184static struct resource * __request_resource(struct resource *root, struct resource *new)
 185{
 186	resource_size_t start = new->start;
 187	resource_size_t end = new->end;
 188	struct resource *tmp, **p;
 189
 190	if (end < start)
 191		return root;
 192	if (start < root->start)
 193		return root;
 194	if (end > root->end)
 195		return root;
 196	p = &root->child;
 197	for (;;) {
 198		tmp = *p;
 199		if (!tmp || tmp->start > end) {
 200			new->sibling = tmp;
 201			*p = new;
 202			new->parent = root;
 203			return NULL;
 204		}
 205		p = &tmp->sibling;
 206		if (tmp->end < start)
 207			continue;
 208		return tmp;
 209	}
 210}
 211
 212static int __release_resource(struct resource *old, bool release_child)
 213{
 214	struct resource *tmp, **p, *chd;
 215
 216	p = &old->parent->child;
 217	for (;;) {
 218		tmp = *p;
 219		if (!tmp)
 220			break;
 221		if (tmp == old) {
 222			if (release_child || !(tmp->child)) {
 223				*p = tmp->sibling;
 224			} else {
 225				for (chd = tmp->child;; chd = chd->sibling) {
 226					chd->parent = tmp->parent;
 227					if (!(chd->sibling))
 228						break;
 229				}
 230				*p = tmp->child;
 231				chd->sibling = tmp->sibling;
 232			}
 233			old->parent = NULL;
 234			return 0;
 235		}
 236		p = &tmp->sibling;
 237	}
 238	return -EINVAL;
 239}
 240
 241static void __release_child_resources(struct resource *r)
 242{
 243	struct resource *tmp, *p;
 244	resource_size_t size;
 245
 246	p = r->child;
 247	r->child = NULL;
 248	while (p) {
 249		tmp = p;
 250		p = p->sibling;
 251
 252		tmp->parent = NULL;
 253		tmp->sibling = NULL;
 254		__release_child_resources(tmp);
 255
 256		printk(KERN_DEBUG "release child resource %pR\n", tmp);
 257		/* need to restore size, and keep flags */
 258		size = resource_size(tmp);
 259		tmp->start = 0;
 260		tmp->end = size - 1;
 261	}
 262}
 263
 264void release_child_resources(struct resource *r)
 265{
 266	write_lock(&resource_lock);
 267	__release_child_resources(r);
 268	write_unlock(&resource_lock);
 269}
 270
 271/**
 272 * request_resource_conflict - request and reserve an I/O or memory resource
 273 * @root: root resource descriptor
 274 * @new: resource descriptor desired by caller
 275 *
 276 * Returns 0 for success, conflict resource on error.
 277 */
 278struct resource *request_resource_conflict(struct resource *root, struct resource *new)
 279{
 280	struct resource *conflict;
 281
 282	write_lock(&resource_lock);
 283	conflict = __request_resource(root, new);
 284	write_unlock(&resource_lock);
 285	return conflict;
 286}
 287
 288/**
 289 * request_resource - request and reserve an I/O or memory resource
 290 * @root: root resource descriptor
 291 * @new: resource descriptor desired by caller
 292 *
 293 * Returns 0 for success, negative error code on error.
 294 */
 295int request_resource(struct resource *root, struct resource *new)
 296{
 297	struct resource *conflict;
 298
 299	conflict = request_resource_conflict(root, new);
 300	return conflict ? -EBUSY : 0;
 301}
 302
 303EXPORT_SYMBOL(request_resource);
 304
 305/**
 306 * release_resource - release a previously reserved resource
 307 * @old: resource pointer
 308 */
 309int release_resource(struct resource *old)
 310{
 311	int retval;
 312
 313	write_lock(&resource_lock);
 314	retval = __release_resource(old, true);
 315	write_unlock(&resource_lock);
 316	return retval;
 317}
 318
 319EXPORT_SYMBOL(release_resource);
 320
 321/**
 322 * find_next_iomem_res - Finds the lowest iomem resource that covers part of
 323 *			 [@start..@end].
 324 *
 325 * If a resource is found, returns 0 and @*res is overwritten with the part
 326 * of the resource that's within [@start..@end]; if none is found, returns
 327 * -ENODEV.  Returns -EINVAL for invalid parameters.
 328 *
 329 * @start:	start address of the resource searched for
 330 * @end:	end address of same resource
 331 * @flags:	flags which the resource must have
 332 * @desc:	descriptor the resource must have
 333 * @res:	return ptr, if resource found
 334 *
 335 * The caller must specify @start, @end, @flags, and @desc
 336 * (which may be IORES_DESC_NONE).
 337 */
 338static int find_next_iomem_res(resource_size_t start, resource_size_t end,
 339			       unsigned long flags, unsigned long desc,
 340			       struct resource *res)
 341{
 342	struct resource *p;
 343
 344	if (!res)
 345		return -EINVAL;
 346
 347	if (start >= end)
 348		return -EINVAL;
 349
 350	read_lock(&resource_lock);
 351
 352	for (p = iomem_resource.child; p; p = next_resource(p)) {
 353		/* If we passed the resource we are looking for, stop */
 354		if (p->start > end) {
 355			p = NULL;
 356			break;
 357		}
 358
 359		/* Skip until we find a range that matches what we look for */
 360		if (p->end < start)
 361			continue;
 362
 363		if ((p->flags & flags) != flags)
 364			continue;
 365		if ((desc != IORES_DESC_NONE) && (desc != p->desc))
 366			continue;
 367
 368		/* Found a match, break */
 369		break;
 370	}
 371
 372	if (p) {
 373		/* copy data */
 374		*res = (struct resource) {
 375			.start = max(start, p->start),
 376			.end = min(end, p->end),
 377			.flags = p->flags,
 378			.desc = p->desc,
 379			.parent = p->parent,
 380		};
 381	}
 382
 383	read_unlock(&resource_lock);
 384	return p ? 0 : -ENODEV;
 385}
 386
 387static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
 388				 unsigned long flags, unsigned long desc,
 389				 void *arg,
 390				 int (*func)(struct resource *, void *))
 391{
 392	struct resource res;
 393	int ret = -EINVAL;
 394
 395	while (start < end &&
 396	       !find_next_iomem_res(start, end, flags, desc, &res)) {
 397		ret = (*func)(&res, arg);
 398		if (ret)
 399			break;
 400
 401		start = res.end + 1;
 402	}
 403
 404	return ret;
 405}
 406
 407/**
 408 * walk_iomem_res_desc - Walks through iomem resources and calls func()
 409 *			 with matching resource ranges.
 410 * *
 411 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
 412 * @flags: I/O resource flags
 413 * @start: start addr
 414 * @end: end addr
 415 * @arg: function argument for the callback @func
 416 * @func: callback function that is called for each qualifying resource area
 417 *
 418 * All the memory ranges which overlap start,end and also match flags and
 419 * desc are valid candidates.
 420 *
 421 * NOTE: For a new descriptor search, define a new IORES_DESC in
 422 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
 423 */
 424int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
 425		u64 end, void *arg, int (*func)(struct resource *, void *))
 426{
 427	return __walk_iomem_res_desc(start, end, flags, desc, arg, func);
 428}
 429EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
 430
 431/*
 432 * This function calls the @func callback against all memory ranges of type
 433 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
 434 * Now, this function is only for System RAM, it deals with full ranges and
 435 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
 436 * ranges.
 437 */
 438int walk_system_ram_res(u64 start, u64 end, void *arg,
 439			int (*func)(struct resource *, void *))
 440{
 441	unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 442
 443	return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
 444				     func);
 445}
 446
 447/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 448 * This function calls the @func callback against all memory ranges, which
 449 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
 450 */
 451int walk_mem_res(u64 start, u64 end, void *arg,
 452		 int (*func)(struct resource *, void *))
 453{
 454	unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 455
 456	return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
 457				     func);
 458}
 459
 460/*
 461 * This function calls the @func callback against all memory ranges of type
 462 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
 463 * It is to be used only for System RAM.
 464 */
 465int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 466			  void *arg, int (*func)(unsigned long, unsigned long, void *))
 467{
 468	resource_size_t start, end;
 469	unsigned long flags;
 470	struct resource res;
 471	unsigned long pfn, end_pfn;
 472	int ret = -EINVAL;
 473
 474	start = (u64) start_pfn << PAGE_SHIFT;
 475	end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 476	flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 477	while (start < end &&
 478	       !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res)) {
 479		pfn = PFN_UP(res.start);
 480		end_pfn = PFN_DOWN(res.end + 1);
 481		if (end_pfn > pfn)
 482			ret = (*func)(pfn, end_pfn - pfn, arg);
 483		if (ret)
 484			break;
 485		start = res.end + 1;
 486	}
 487	return ret;
 488}
 489
 490static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
 491{
 492	return 1;
 493}
 494
 495/*
 496 * This generic page_is_ram() returns true if specified address is
 497 * registered as System RAM in iomem_resource list.
 498 */
 499int __weak page_is_ram(unsigned long pfn)
 500{
 501	return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
 502}
 503EXPORT_SYMBOL_GPL(page_is_ram);
 504
 505static int __region_intersects(resource_size_t start, size_t size,
 506			unsigned long flags, unsigned long desc)
 
 507{
 508	struct resource res;
 509	int type = 0; int other = 0;
 510	struct resource *p;
 511
 512	res.start = start;
 513	res.end = start + size - 1;
 514
 515	for (p = iomem_resource.child; p ; p = p->sibling) {
 516		bool is_type = (((p->flags & flags) == flags) &&
 517				((desc == IORES_DESC_NONE) ||
 518				 (desc == p->desc)));
 519
 520		if (resource_overlaps(p, &res))
 521			is_type ? type++ : other++;
 522	}
 523
 524	if (type == 0)
 525		return REGION_DISJOINT;
 526
 527	if (other == 0)
 528		return REGION_INTERSECTS;
 529
 530	return REGION_MIXED;
 531}
 532
 533/**
 534 * region_intersects() - determine intersection of region with known resources
 535 * @start: region start address
 536 * @size: size of region
 537 * @flags: flags of resource (in iomem_resource)
 538 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
 539 *
 540 * Check if the specified region partially overlaps or fully eclipses a
 541 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
 542 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
 543 * return REGION_MIXED if the region overlaps @flags/@desc and another
 544 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
 545 * and no other defined resource. Note that REGION_INTERSECTS is also
 546 * returned in the case when the specified region overlaps RAM and undefined
 547 * memory holes.
 548 *
 549 * region_intersect() is used by memory remapping functions to ensure
 550 * the user is not remapping RAM and is a vast speed up over walking
 551 * through the resource table page by page.
 552 */
 553int region_intersects(resource_size_t start, size_t size, unsigned long flags,
 554		      unsigned long desc)
 555{
 556	int ret;
 557
 558	read_lock(&resource_lock);
 559	ret = __region_intersects(start, size, flags, desc);
 560	read_unlock(&resource_lock);
 561
 562	return ret;
 563}
 564EXPORT_SYMBOL_GPL(region_intersects);
 565
 566void __weak arch_remove_reservations(struct resource *avail)
 567{
 568}
 569
 570static resource_size_t simple_align_resource(void *data,
 571					     const struct resource *avail,
 572					     resource_size_t size,
 573					     resource_size_t align)
 574{
 575	return avail->start;
 576}
 577
 578static void resource_clip(struct resource *res, resource_size_t min,
 579			  resource_size_t max)
 580{
 581	if (res->start < min)
 582		res->start = min;
 583	if (res->end > max)
 584		res->end = max;
 585}
 586
 587/*
 588 * Find empty slot in the resource tree with the given range and
 589 * alignment constraints
 590 */
 591static int __find_resource(struct resource *root, struct resource *old,
 592			 struct resource *new,
 593			 resource_size_t  size,
 594			 struct resource_constraint *constraint)
 595{
 596	struct resource *this = root->child;
 597	struct resource tmp = *new, avail, alloc;
 598
 599	tmp.start = root->start;
 600	/*
 601	 * Skip past an allocated resource that starts at 0, since the assignment
 602	 * of this->start - 1 to tmp->end below would cause an underflow.
 603	 */
 604	if (this && this->start == root->start) {
 605		tmp.start = (this == old) ? old->start : this->end + 1;
 606		this = this->sibling;
 607	}
 608	for(;;) {
 609		if (this)
 610			tmp.end = (this == old) ?  this->end : this->start - 1;
 611		else
 612			tmp.end = root->end;
 613
 614		if (tmp.end < tmp.start)
 615			goto next;
 616
 617		resource_clip(&tmp, constraint->min, constraint->max);
 618		arch_remove_reservations(&tmp);
 619
 620		/* Check for overflow after ALIGN() */
 621		avail.start = ALIGN(tmp.start, constraint->align);
 622		avail.end = tmp.end;
 623		avail.flags = new->flags & ~IORESOURCE_UNSET;
 624		if (avail.start >= tmp.start) {
 625			alloc.flags = avail.flags;
 626			alloc.start = constraint->alignf(constraint->alignf_data, &avail,
 627					size, constraint->align);
 628			alloc.end = alloc.start + size - 1;
 629			if (alloc.start <= alloc.end &&
 630			    resource_contains(&avail, &alloc)) {
 631				new->start = alloc.start;
 632				new->end = alloc.end;
 633				return 0;
 634			}
 635		}
 636
 637next:		if (!this || this->end == root->end)
 638			break;
 639
 640		if (this != old)
 641			tmp.start = this->end + 1;
 642		this = this->sibling;
 643	}
 644	return -EBUSY;
 645}
 646
 647/*
 648 * Find empty slot in the resource tree given range and alignment.
 649 */
 650static int find_resource(struct resource *root, struct resource *new,
 651			resource_size_t size,
 652			struct resource_constraint  *constraint)
 653{
 654	return  __find_resource(root, NULL, new, size, constraint);
 655}
 656
 657/**
 658 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
 659 *	The resource will be relocated if the new size cannot be reallocated in the
 660 *	current location.
 661 *
 662 * @root: root resource descriptor
 663 * @old:  resource descriptor desired by caller
 664 * @newsize: new size of the resource descriptor
 665 * @constraint: the size and alignment constraints to be met.
 666 */
 667static int reallocate_resource(struct resource *root, struct resource *old,
 668			       resource_size_t newsize,
 669			       struct resource_constraint *constraint)
 670{
 671	int err=0;
 672	struct resource new = *old;
 673	struct resource *conflict;
 674
 675	write_lock(&resource_lock);
 676
 677	if ((err = __find_resource(root, old, &new, newsize, constraint)))
 678		goto out;
 679
 680	if (resource_contains(&new, old)) {
 681		old->start = new.start;
 682		old->end = new.end;
 683		goto out;
 684	}
 685
 686	if (old->child) {
 687		err = -EBUSY;
 688		goto out;
 689	}
 690
 691	if (resource_contains(old, &new)) {
 692		old->start = new.start;
 693		old->end = new.end;
 694	} else {
 695		__release_resource(old, true);
 696		*old = new;
 697		conflict = __request_resource(root, old);
 698		BUG_ON(conflict);
 699	}
 700out:
 701	write_unlock(&resource_lock);
 702	return err;
 703}
 704
 705
 706/**
 707 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
 708 * 	The resource will be reallocated with a new size if it was already allocated
 709 * @root: root resource descriptor
 710 * @new: resource descriptor desired by caller
 711 * @size: requested resource region size
 712 * @min: minimum boundary to allocate
 713 * @max: maximum boundary to allocate
 714 * @align: alignment requested, in bytes
 715 * @alignf: alignment function, optional, called if not NULL
 716 * @alignf_data: arbitrary data to pass to the @alignf function
 717 */
 718int allocate_resource(struct resource *root, struct resource *new,
 719		      resource_size_t size, resource_size_t min,
 720		      resource_size_t max, resource_size_t align,
 721		      resource_size_t (*alignf)(void *,
 722						const struct resource *,
 723						resource_size_t,
 724						resource_size_t),
 725		      void *alignf_data)
 726{
 727	int err;
 728	struct resource_constraint constraint;
 729
 730	if (!alignf)
 731		alignf = simple_align_resource;
 732
 733	constraint.min = min;
 734	constraint.max = max;
 735	constraint.align = align;
 736	constraint.alignf = alignf;
 737	constraint.alignf_data = alignf_data;
 738
 739	if ( new->parent ) {
 740		/* resource is already allocated, try reallocating with
 741		   the new constraints */
 742		return reallocate_resource(root, new, size, &constraint);
 743	}
 744
 745	write_lock(&resource_lock);
 746	err = find_resource(root, new, size, &constraint);
 747	if (err >= 0 && __request_resource(root, new))
 748		err = -EBUSY;
 749	write_unlock(&resource_lock);
 750	return err;
 751}
 752
 753EXPORT_SYMBOL(allocate_resource);
 754
 755/**
 756 * lookup_resource - find an existing resource by a resource start address
 757 * @root: root resource descriptor
 758 * @start: resource start address
 759 *
 760 * Returns a pointer to the resource if found, NULL otherwise
 761 */
 762struct resource *lookup_resource(struct resource *root, resource_size_t start)
 763{
 764	struct resource *res;
 765
 766	read_lock(&resource_lock);
 767	for (res = root->child; res; res = res->sibling) {
 768		if (res->start == start)
 769			break;
 770	}
 771	read_unlock(&resource_lock);
 772
 773	return res;
 774}
 775
 776/*
 777 * Insert a resource into the resource tree. If successful, return NULL,
 778 * otherwise return the conflicting resource (compare to __request_resource())
 779 */
 780static struct resource * __insert_resource(struct resource *parent, struct resource *new)
 781{
 782	struct resource *first, *next;
 783
 784	for (;; parent = first) {
 785		first = __request_resource(parent, new);
 786		if (!first)
 787			return first;
 788
 789		if (first == parent)
 790			return first;
 791		if (WARN_ON(first == new))	/* duplicated insertion */
 792			return first;
 793
 794		if ((first->start > new->start) || (first->end < new->end))
 795			break;
 796		if ((first->start == new->start) && (first->end == new->end))
 797			break;
 798	}
 799
 800	for (next = first; ; next = next->sibling) {
 801		/* Partial overlap? Bad, and unfixable */
 802		if (next->start < new->start || next->end > new->end)
 803			return next;
 804		if (!next->sibling)
 805			break;
 806		if (next->sibling->start > new->end)
 807			break;
 808	}
 809
 810	new->parent = parent;
 811	new->sibling = next->sibling;
 812	new->child = first;
 813
 814	next->sibling = NULL;
 815	for (next = first; next; next = next->sibling)
 816		next->parent = new;
 817
 818	if (parent->child == first) {
 819		parent->child = new;
 820	} else {
 821		next = parent->child;
 822		while (next->sibling != first)
 823			next = next->sibling;
 824		next->sibling = new;
 825	}
 826	return NULL;
 827}
 828
 829/**
 830 * insert_resource_conflict - Inserts resource in the resource tree
 831 * @parent: parent of the new resource
 832 * @new: new resource to insert
 833 *
 834 * Returns 0 on success, conflict resource if the resource can't be inserted.
 835 *
 836 * This function is equivalent to request_resource_conflict when no conflict
 837 * happens. If a conflict happens, and the conflicting resources
 838 * entirely fit within the range of the new resource, then the new
 839 * resource is inserted and the conflicting resources become children of
 840 * the new resource.
 841 *
 842 * This function is intended for producers of resources, such as FW modules
 843 * and bus drivers.
 844 */
 845struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
 846{
 847	struct resource *conflict;
 848
 849	write_lock(&resource_lock);
 850	conflict = __insert_resource(parent, new);
 851	write_unlock(&resource_lock);
 852	return conflict;
 853}
 854
 855/**
 856 * insert_resource - Inserts a resource in the resource tree
 857 * @parent: parent of the new resource
 858 * @new: new resource to insert
 859 *
 860 * Returns 0 on success, -EBUSY if the resource can't be inserted.
 861 *
 862 * This function is intended for producers of resources, such as FW modules
 863 * and bus drivers.
 864 */
 865int insert_resource(struct resource *parent, struct resource *new)
 866{
 867	struct resource *conflict;
 868
 869	conflict = insert_resource_conflict(parent, new);
 870	return conflict ? -EBUSY : 0;
 871}
 872EXPORT_SYMBOL_GPL(insert_resource);
 873
 874/**
 875 * insert_resource_expand_to_fit - Insert a resource into the resource tree
 876 * @root: root resource descriptor
 877 * @new: new resource to insert
 878 *
 879 * Insert a resource into the resource tree, possibly expanding it in order
 880 * to make it encompass any conflicting resources.
 881 */
 882void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 883{
 884	if (new->parent)
 885		return;
 886
 887	write_lock(&resource_lock);
 888	for (;;) {
 889		struct resource *conflict;
 890
 891		conflict = __insert_resource(root, new);
 892		if (!conflict)
 893			break;
 894		if (conflict == root)
 895			break;
 896
 897		/* Ok, expand resource to cover the conflict, then try again .. */
 898		if (conflict->start < new->start)
 899			new->start = conflict->start;
 900		if (conflict->end > new->end)
 901			new->end = conflict->end;
 902
 903		printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
 904	}
 905	write_unlock(&resource_lock);
 906}
 
 
 
 
 
 
 
 907
 908/**
 909 * remove_resource - Remove a resource in the resource tree
 910 * @old: resource to remove
 911 *
 912 * Returns 0 on success, -EINVAL if the resource is not valid.
 913 *
 914 * This function removes a resource previously inserted by insert_resource()
 915 * or insert_resource_conflict(), and moves the children (if any) up to
 916 * where they were before.  insert_resource() and insert_resource_conflict()
 917 * insert a new resource, and move any conflicting resources down to the
 918 * children of the new resource.
 919 *
 920 * insert_resource(), insert_resource_conflict() and remove_resource() are
 921 * intended for producers of resources, such as FW modules and bus drivers.
 922 */
 923int remove_resource(struct resource *old)
 924{
 925	int retval;
 926
 927	write_lock(&resource_lock);
 928	retval = __release_resource(old, false);
 929	write_unlock(&resource_lock);
 930	return retval;
 931}
 932EXPORT_SYMBOL_GPL(remove_resource);
 933
 934static int __adjust_resource(struct resource *res, resource_size_t start,
 935				resource_size_t size)
 936{
 937	struct resource *tmp, *parent = res->parent;
 938	resource_size_t end = start + size - 1;
 939	int result = -EBUSY;
 940
 941	if (!parent)
 942		goto skip;
 943
 944	if ((start < parent->start) || (end > parent->end))
 945		goto out;
 946
 947	if (res->sibling && (res->sibling->start <= end))
 948		goto out;
 949
 950	tmp = parent->child;
 951	if (tmp != res) {
 952		while (tmp->sibling != res)
 953			tmp = tmp->sibling;
 954		if (start <= tmp->end)
 955			goto out;
 956	}
 957
 958skip:
 959	for (tmp = res->child; tmp; tmp = tmp->sibling)
 960		if ((tmp->start < start) || (tmp->end > end))
 961			goto out;
 962
 963	res->start = start;
 964	res->end = end;
 965	result = 0;
 966
 967 out:
 968	return result;
 969}
 970
 971/**
 972 * adjust_resource - modify a resource's start and size
 973 * @res: resource to modify
 974 * @start: new start value
 975 * @size: new size
 976 *
 977 * Given an existing resource, change its start and size to match the
 978 * arguments.  Returns 0 on success, -EBUSY if it can't fit.
 979 * Existing children of the resource are assumed to be immutable.
 980 */
 981int adjust_resource(struct resource *res, resource_size_t start,
 982		    resource_size_t size)
 983{
 984	int result;
 985
 986	write_lock(&resource_lock);
 987	result = __adjust_resource(res, start, size);
 988	write_unlock(&resource_lock);
 989	return result;
 990}
 991EXPORT_SYMBOL(adjust_resource);
 992
 993static void __init
 994__reserve_region_with_split(struct resource *root, resource_size_t start,
 995			    resource_size_t end, const char *name)
 996{
 997	struct resource *parent = root;
 998	struct resource *conflict;
 999	struct resource *res = alloc_resource(GFP_ATOMIC);
1000	struct resource *next_res = NULL;
1001	int type = resource_type(root);
1002
1003	if (!res)
1004		return;
1005
1006	res->name = name;
1007	res->start = start;
1008	res->end = end;
1009	res->flags = type | IORESOURCE_BUSY;
1010	res->desc = IORES_DESC_NONE;
1011
1012	while (1) {
1013
1014		conflict = __request_resource(parent, res);
1015		if (!conflict) {
1016			if (!next_res)
1017				break;
1018			res = next_res;
1019			next_res = NULL;
1020			continue;
1021		}
1022
1023		/* conflict covered whole area */
1024		if (conflict->start <= res->start &&
1025				conflict->end >= res->end) {
1026			free_resource(res);
1027			WARN_ON(next_res);
1028			break;
1029		}
1030
1031		/* failed, split and try again */
1032		if (conflict->start > res->start) {
1033			end = res->end;
1034			res->end = conflict->start - 1;
1035			if (conflict->end < end) {
1036				next_res = alloc_resource(GFP_ATOMIC);
1037				if (!next_res) {
1038					free_resource(res);
1039					break;
1040				}
1041				next_res->name = name;
1042				next_res->start = conflict->end + 1;
1043				next_res->end = end;
1044				next_res->flags = type | IORESOURCE_BUSY;
1045				next_res->desc = IORES_DESC_NONE;
1046			}
1047		} else {
1048			res->start = conflict->end + 1;
1049		}
1050	}
1051
1052}
1053
1054void __init
1055reserve_region_with_split(struct resource *root, resource_size_t start,
1056			  resource_size_t end, const char *name)
1057{
1058	int abort = 0;
1059
1060	write_lock(&resource_lock);
1061	if (root->start > start || root->end < end) {
1062		pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1063		       (unsigned long long)start, (unsigned long long)end,
1064		       root);
1065		if (start > root->end || end < root->start)
1066			abort = 1;
1067		else {
1068			if (end > root->end)
1069				end = root->end;
1070			if (start < root->start)
1071				start = root->start;
1072			pr_err("fixing request to [0x%llx-0x%llx]\n",
1073			       (unsigned long long)start,
1074			       (unsigned long long)end);
1075		}
1076		dump_stack();
1077	}
1078	if (!abort)
1079		__reserve_region_with_split(root, start, end, name);
1080	write_unlock(&resource_lock);
1081}
1082
1083/**
1084 * resource_alignment - calculate resource's alignment
1085 * @res: resource pointer
1086 *
1087 * Returns alignment on success, 0 (invalid alignment) on failure.
1088 */
1089resource_size_t resource_alignment(struct resource *res)
1090{
1091	switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1092	case IORESOURCE_SIZEALIGN:
1093		return resource_size(res);
1094	case IORESOURCE_STARTALIGN:
1095		return res->start;
1096	default:
1097		return 0;
1098	}
1099}
1100
1101/*
1102 * This is compatibility stuff for IO resources.
1103 *
1104 * Note how this, unlike the above, knows about
1105 * the IO flag meanings (busy etc).
1106 *
1107 * request_region creates a new busy region.
1108 *
1109 * release_region releases a matching busy region.
1110 */
1111
1112static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1113
1114static struct inode *iomem_inode;
1115
1116#ifdef CONFIG_IO_STRICT_DEVMEM
1117static void revoke_iomem(struct resource *res)
1118{
1119	/* pairs with smp_store_release() in iomem_init_inode() */
1120	struct inode *inode = smp_load_acquire(&iomem_inode);
1121
1122	/*
1123	 * Check that the initialization has completed. Losing the race
1124	 * is ok because it means drivers are claiming resources before
1125	 * the fs_initcall level of init and prevent iomem_get_mapping users
1126	 * from establishing mappings.
1127	 */
1128	if (!inode)
1129		return;
1130
1131	/*
1132	 * The expectation is that the driver has successfully marked
1133	 * the resource busy by this point, so devmem_is_allowed()
1134	 * should start returning false, however for performance this
1135	 * does not iterate the entire resource range.
1136	 */
1137	if (devmem_is_allowed(PHYS_PFN(res->start)) &&
1138	    devmem_is_allowed(PHYS_PFN(res->end))) {
1139		/*
1140		 * *cringe* iomem=relaxed says "go ahead, what's the
1141		 * worst that can happen?"
1142		 */
1143		return;
1144	}
1145
1146	unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1);
1147}
1148#else
1149static void revoke_iomem(struct resource *res) {}
1150#endif
1151
1152struct address_space *iomem_get_mapping(void)
1153{
1154	/*
1155	 * This function is only called from file open paths, hence guaranteed
1156	 * that fs_initcalls have completed and no need to check for NULL. But
1157	 * since revoke_iomem can be called before the initcall we still need
1158	 * the barrier to appease checkers.
1159	 */
1160	return smp_load_acquire(&iomem_inode)->i_mapping;
1161}
1162
1163static int __request_region_locked(struct resource *res, struct resource *parent,
1164				   resource_size_t start, resource_size_t n,
1165				   const char *name, int flags)
1166{
1167	DECLARE_WAITQUEUE(wait, current);
1168
1169	res->name = name;
1170	res->start = start;
1171	res->end = start + n - 1;
1172
1173	for (;;) {
1174		struct resource *conflict;
1175
1176		res->flags = resource_type(parent) | resource_ext_type(parent);
1177		res->flags |= IORESOURCE_BUSY | flags;
1178		res->desc = parent->desc;
1179
1180		conflict = __request_resource(parent, res);
1181		if (!conflict)
1182			break;
1183		/*
1184		 * mm/hmm.c reserves physical addresses which then
1185		 * become unavailable to other users.  Conflicts are
1186		 * not expected.  Warn to aid debugging if encountered.
1187		 */
1188		if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1189			pr_warn("Unaddressable device %s %pR conflicts with %pR",
1190				conflict->name, conflict, res);
1191		}
1192		if (conflict != parent) {
1193			if (!(conflict->flags & IORESOURCE_BUSY)) {
1194				parent = conflict;
1195				continue;
1196			}
1197		}
1198		if (conflict->flags & flags & IORESOURCE_MUXED) {
1199			add_wait_queue(&muxed_resource_wait, &wait);
1200			write_unlock(&resource_lock);
1201			set_current_state(TASK_UNINTERRUPTIBLE);
1202			schedule();
1203			remove_wait_queue(&muxed_resource_wait, &wait);
1204			write_lock(&resource_lock);
1205			continue;
1206		}
1207		/* Uhhuh, that didn't work out.. */
1208		return -EBUSY;
1209	}
1210
1211	return 0;
1212}
1213
1214/**
1215 * __request_region - create a new busy resource region
1216 * @parent: parent resource descriptor
1217 * @start: resource start address
1218 * @n: resource region size
1219 * @name: reserving caller's ID string
1220 * @flags: IO resource flags
1221 */
1222struct resource *__request_region(struct resource *parent,
1223				  resource_size_t start, resource_size_t n,
1224				  const char *name, int flags)
1225{
1226	struct resource *res = alloc_resource(GFP_KERNEL);
1227	int ret;
1228
1229	if (!res)
1230		return NULL;
1231
1232	write_lock(&resource_lock);
1233	ret = __request_region_locked(res, parent, start, n, name, flags);
1234	write_unlock(&resource_lock);
1235
1236	if (ret) {
1237		free_resource(res);
1238		return NULL;
1239	}
1240
1241	if (parent == &iomem_resource)
1242		revoke_iomem(res);
1243
1244	return res;
1245}
1246EXPORT_SYMBOL(__request_region);
1247
1248/**
1249 * __release_region - release a previously reserved resource region
1250 * @parent: parent resource descriptor
1251 * @start: resource start address
1252 * @n: resource region size
1253 *
1254 * The described resource region must match a currently busy region.
1255 */
1256void __release_region(struct resource *parent, resource_size_t start,
1257		      resource_size_t n)
1258{
1259	struct resource **p;
1260	resource_size_t end;
1261
1262	p = &parent->child;
1263	end = start + n - 1;
1264
1265	write_lock(&resource_lock);
1266
1267	for (;;) {
1268		struct resource *res = *p;
1269
1270		if (!res)
1271			break;
1272		if (res->start <= start && res->end >= end) {
1273			if (!(res->flags & IORESOURCE_BUSY)) {
1274				p = &res->child;
1275				continue;
1276			}
1277			if (res->start != start || res->end != end)
1278				break;
1279			*p = res->sibling;
1280			write_unlock(&resource_lock);
1281			if (res->flags & IORESOURCE_MUXED)
1282				wake_up(&muxed_resource_wait);
1283			free_resource(res);
1284			return;
1285		}
1286		p = &res->sibling;
1287	}
1288
1289	write_unlock(&resource_lock);
1290
1291	printk(KERN_WARNING "Trying to free nonexistent resource "
1292		"<%016llx-%016llx>\n", (unsigned long long)start,
1293		(unsigned long long)end);
1294}
1295EXPORT_SYMBOL(__release_region);
1296
1297#ifdef CONFIG_MEMORY_HOTREMOVE
1298/**
1299 * release_mem_region_adjustable - release a previously reserved memory region
1300 * @start: resource start address
1301 * @size: resource region size
1302 *
1303 * This interface is intended for memory hot-delete.  The requested region
1304 * is released from a currently busy memory resource.  The requested region
1305 * must either match exactly or fit into a single busy resource entry.  In
1306 * the latter case, the remaining resource is adjusted accordingly.
1307 * Existing children of the busy memory resource must be immutable in the
1308 * request.
1309 *
1310 * Note:
1311 * - Additional release conditions, such as overlapping region, can be
1312 *   supported after they are confirmed as valid cases.
1313 * - When a busy memory resource gets split into two entries, the code
1314 *   assumes that all children remain in the lower address entry for
1315 *   simplicity.  Enhance this logic when necessary.
1316 */
1317void release_mem_region_adjustable(resource_size_t start, resource_size_t size)
1318{
1319	struct resource *parent = &iomem_resource;
1320	struct resource *new_res = NULL;
1321	bool alloc_nofail = false;
1322	struct resource **p;
1323	struct resource *res;
1324	resource_size_t end;
1325
1326	end = start + size - 1;
1327	if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
1328		return;
1329
1330	/*
1331	 * We free up quite a lot of memory on memory hotunplug (esp., memap),
1332	 * just before releasing the region. This is highly unlikely to
1333	 * fail - let's play save and make it never fail as the caller cannot
1334	 * perform any error handling (e.g., trying to re-add memory will fail
1335	 * similarly).
1336	 */
1337retry:
1338	new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
1339
1340	p = &parent->child;
1341	write_lock(&resource_lock);
1342
1343	while ((res = *p)) {
1344		if (res->start >= end)
1345			break;
1346
1347		/* look for the next resource if it does not fit into */
1348		if (res->start > start || res->end < end) {
1349			p = &res->sibling;
1350			continue;
1351		}
1352
1353		/*
1354		 * All memory regions added from memory-hotplug path have the
1355		 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1356		 * this flag, we know that we are dealing with a resource coming
1357		 * from HMM/devm. HMM/devm use another mechanism to add/release
1358		 * a resource. This goes via devm_request_mem_region and
1359		 * devm_release_mem_region.
1360		 * HMM/devm take care to release their resources when they want,
1361		 * so if we are dealing with them, let us just back off here.
1362		 */
1363		if (!(res->flags & IORESOURCE_SYSRAM)) {
1364			break;
1365		}
1366
1367		if (!(res->flags & IORESOURCE_MEM))
1368			break;
1369
1370		if (!(res->flags & IORESOURCE_BUSY)) {
1371			p = &res->child;
1372			continue;
1373		}
1374
1375		/* found the target resource; let's adjust accordingly */
1376		if (res->start == start && res->end == end) {
1377			/* free the whole entry */
1378			*p = res->sibling;
1379			free_resource(res);
1380		} else if (res->start == start && res->end != end) {
1381			/* adjust the start */
1382			WARN_ON_ONCE(__adjust_resource(res, end + 1,
1383						       res->end - end));
1384		} else if (res->start != start && res->end == end) {
1385			/* adjust the end */
1386			WARN_ON_ONCE(__adjust_resource(res, res->start,
1387						       start - res->start));
1388		} else {
1389			/* split into two entries - we need a new resource */
1390			if (!new_res) {
1391				new_res = alloc_resource(GFP_ATOMIC);
1392				if (!new_res) {
1393					alloc_nofail = true;
1394					write_unlock(&resource_lock);
1395					goto retry;
1396				}
1397			}
1398			new_res->name = res->name;
1399			new_res->start = end + 1;
1400			new_res->end = res->end;
1401			new_res->flags = res->flags;
1402			new_res->desc = res->desc;
1403			new_res->parent = res->parent;
1404			new_res->sibling = res->sibling;
1405			new_res->child = NULL;
1406
1407			if (WARN_ON_ONCE(__adjust_resource(res, res->start,
1408							   start - res->start)))
1409				break;
1410			res->sibling = new_res;
1411			new_res = NULL;
1412		}
1413
1414		break;
1415	}
1416
1417	write_unlock(&resource_lock);
1418	free_resource(new_res);
1419}
1420#endif	/* CONFIG_MEMORY_HOTREMOVE */
1421
1422#ifdef CONFIG_MEMORY_HOTPLUG
1423static bool system_ram_resources_mergeable(struct resource *r1,
1424					   struct resource *r2)
1425{
1426	/* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1427	return r1->flags == r2->flags && r1->end + 1 == r2->start &&
1428	       r1->name == r2->name && r1->desc == r2->desc &&
1429	       !r1->child && !r2->child;
1430}
1431
1432/**
1433 * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1434 *	merge it with adjacent, mergeable resources
1435 * @res: resource descriptor
1436 *
1437 * This interface is intended for memory hotplug, whereby lots of contiguous
1438 * system ram resources are added (e.g., via add_memory*()) by a driver, and
1439 * the actual resource boundaries are not of interest (e.g., it might be
1440 * relevant for DIMMs). Only resources that are marked mergeable, that have the
1441 * same parent, and that don't have any children are considered. All mergeable
1442 * resources must be immutable during the request.
1443 *
1444 * Note:
1445 * - The caller has to make sure that no pointers to resources that are
1446 *   marked mergeable are used anymore after this call - the resource might
1447 *   be freed and the pointer might be stale!
1448 * - release_mem_region_adjustable() will split on demand on memory hotunplug
1449 */
1450void merge_system_ram_resource(struct resource *res)
1451{
1452	const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
1453	struct resource *cur;
1454
1455	if (WARN_ON_ONCE((res->flags & flags) != flags))
1456		return;
1457
1458	write_lock(&resource_lock);
1459	res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
1460
1461	/* Try to merge with next item in the list. */
1462	cur = res->sibling;
1463	if (cur && system_ram_resources_mergeable(res, cur)) {
1464		res->end = cur->end;
1465		res->sibling = cur->sibling;
1466		free_resource(cur);
1467	}
1468
1469	/* Try to merge with previous item in the list. */
1470	cur = res->parent->child;
1471	while (cur && cur->sibling != res)
1472		cur = cur->sibling;
1473	if (cur && system_ram_resources_mergeable(cur, res)) {
1474		cur->end = res->end;
1475		cur->sibling = res->sibling;
1476		free_resource(res);
1477	}
1478	write_unlock(&resource_lock);
1479}
1480#endif	/* CONFIG_MEMORY_HOTPLUG */
1481
1482/*
1483 * Managed region resource
1484 */
1485static void devm_resource_release(struct device *dev, void *ptr)
1486{
1487	struct resource **r = ptr;
1488
1489	release_resource(*r);
1490}
1491
1492/**
1493 * devm_request_resource() - request and reserve an I/O or memory resource
1494 * @dev: device for which to request the resource
1495 * @root: root of the resource tree from which to request the resource
1496 * @new: descriptor of the resource to request
1497 *
1498 * This is a device-managed version of request_resource(). There is usually
1499 * no need to release resources requested by this function explicitly since
1500 * that will be taken care of when the device is unbound from its driver.
1501 * If for some reason the resource needs to be released explicitly, because
1502 * of ordering issues for example, drivers must call devm_release_resource()
1503 * rather than the regular release_resource().
1504 *
1505 * When a conflict is detected between any existing resources and the newly
1506 * requested resource, an error message will be printed.
1507 *
1508 * Returns 0 on success or a negative error code on failure.
1509 */
1510int devm_request_resource(struct device *dev, struct resource *root,
1511			  struct resource *new)
1512{
1513	struct resource *conflict, **ptr;
1514
1515	ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1516	if (!ptr)
1517		return -ENOMEM;
1518
1519	*ptr = new;
1520
1521	conflict = request_resource_conflict(root, new);
1522	if (conflict) {
1523		dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1524			new, conflict->name, conflict);
1525		devres_free(ptr);
1526		return -EBUSY;
1527	}
1528
1529	devres_add(dev, ptr);
1530	return 0;
1531}
1532EXPORT_SYMBOL(devm_request_resource);
1533
1534static int devm_resource_match(struct device *dev, void *res, void *data)
1535{
1536	struct resource **ptr = res;
1537
1538	return *ptr == data;
1539}
1540
1541/**
1542 * devm_release_resource() - release a previously requested resource
1543 * @dev: device for which to release the resource
1544 * @new: descriptor of the resource to release
1545 *
1546 * Releases a resource previously requested using devm_request_resource().
1547 */
1548void devm_release_resource(struct device *dev, struct resource *new)
1549{
1550	WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1551			       new));
1552}
1553EXPORT_SYMBOL(devm_release_resource);
1554
1555struct region_devres {
1556	struct resource *parent;
1557	resource_size_t start;
1558	resource_size_t n;
1559};
1560
1561static void devm_region_release(struct device *dev, void *res)
1562{
1563	struct region_devres *this = res;
1564
1565	__release_region(this->parent, this->start, this->n);
1566}
1567
1568static int devm_region_match(struct device *dev, void *res, void *match_data)
1569{
1570	struct region_devres *this = res, *match = match_data;
1571
1572	return this->parent == match->parent &&
1573		this->start == match->start && this->n == match->n;
1574}
1575
1576struct resource *
1577__devm_request_region(struct device *dev, struct resource *parent,
1578		      resource_size_t start, resource_size_t n, const char *name)
1579{
1580	struct region_devres *dr = NULL;
1581	struct resource *res;
1582
1583	dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1584			  GFP_KERNEL);
1585	if (!dr)
1586		return NULL;
1587
1588	dr->parent = parent;
1589	dr->start = start;
1590	dr->n = n;
1591
1592	res = __request_region(parent, start, n, name, 0);
1593	if (res)
1594		devres_add(dev, dr);
1595	else
1596		devres_free(dr);
1597
1598	return res;
1599}
1600EXPORT_SYMBOL(__devm_request_region);
1601
1602void __devm_release_region(struct device *dev, struct resource *parent,
1603			   resource_size_t start, resource_size_t n)
1604{
1605	struct region_devres match_data = { parent, start, n };
1606
1607	__release_region(parent, start, n);
1608	WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1609			       &match_data));
1610}
1611EXPORT_SYMBOL(__devm_release_region);
1612
1613/*
1614 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1615 */
1616#define MAXRESERVE 4
1617static int __init reserve_setup(char *str)
1618{
1619	static int reserved;
1620	static struct resource reserve[MAXRESERVE];
1621
1622	for (;;) {
1623		unsigned int io_start, io_num;
1624		int x = reserved;
1625		struct resource *parent;
1626
1627		if (get_option(&str, &io_start) != 2)
1628			break;
1629		if (get_option(&str, &io_num) == 0)
1630			break;
1631		if (x < MAXRESERVE) {
1632			struct resource *res = reserve + x;
1633
1634			/*
1635			 * If the region starts below 0x10000, we assume it's
1636			 * I/O port space; otherwise assume it's memory.
1637			 */
1638			if (io_start < 0x10000) {
1639				res->flags = IORESOURCE_IO;
1640				parent = &ioport_resource;
1641			} else {
1642				res->flags = IORESOURCE_MEM;
1643				parent = &iomem_resource;
1644			}
1645			res->name = "reserved";
1646			res->start = io_start;
1647			res->end = io_start + io_num - 1;
1648			res->flags |= IORESOURCE_BUSY;
1649			res->desc = IORES_DESC_NONE;
1650			res->child = NULL;
1651			if (request_resource(parent, res) == 0)
1652				reserved = x+1;
1653		}
1654	}
1655	return 1;
1656}
1657__setup("reserve=", reserve_setup);
1658
1659/*
1660 * Check if the requested addr and size spans more than any slot in the
1661 * iomem resource tree.
1662 */
1663int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1664{
1665	struct resource *p = &iomem_resource;
 
1666	int err = 0;
1667	loff_t l;
1668
1669	read_lock(&resource_lock);
1670	for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1671		/*
1672		 * We can probably skip the resources without
1673		 * IORESOURCE_IO attribute?
1674		 */
1675		if (p->start >= addr + size)
1676			continue;
1677		if (p->end < addr)
1678			continue;
1679		if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1680		    PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1681			continue;
1682		/*
1683		 * if a resource is "BUSY", it's not a hardware resource
1684		 * but a driver mapping of such a resource; we don't want
1685		 * to warn for those; some drivers legitimately map only
1686		 * partial hardware resources. (example: vesafb)
1687		 */
1688		if (p->flags & IORESOURCE_BUSY)
1689			continue;
1690
1691		printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1692		       (unsigned long long)addr,
1693		       (unsigned long long)(addr + size - 1),
1694		       p->name, p);
1695		err = -1;
1696		break;
1697	}
1698	read_unlock(&resource_lock);
1699
1700	return err;
1701}
1702
1703#ifdef CONFIG_STRICT_DEVMEM
1704static int strict_iomem_checks = 1;
1705#else
1706static int strict_iomem_checks;
1707#endif
1708
1709/*
1710 * check if an address is reserved in the iomem resource tree
1711 * returns true if reserved, false if not reserved.
 
 
1712 */
1713bool iomem_is_exclusive(u64 addr)
1714{
1715	struct resource *p = &iomem_resource;
1716	bool err = false;
1717	loff_t l;
1718	int size = PAGE_SIZE;
1719
1720	if (!strict_iomem_checks)
1721		return false;
1722
1723	addr = addr & PAGE_MASK;
1724
1725	read_lock(&resource_lock);
1726	for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1727		/*
1728		 * We can probably skip the resources without
1729		 * IORESOURCE_IO attribute?
1730		 */
1731		if (p->start >= addr + size)
1732			break;
1733		if (p->end < addr)
 
1734			continue;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1735		/*
1736		 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1737		 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1738		 * resource is busy.
1739		 */
1740		if ((p->flags & IORESOURCE_BUSY) == 0)
1741			continue;
1742		if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1743				|| p->flags & IORESOURCE_EXCLUSIVE) {
1744			err = true;
1745			break;
1746		}
1747	}
1748	read_unlock(&resource_lock);
1749
1750	return err;
1751}
1752
 
 
 
 
 
 
1753struct resource_entry *resource_list_create_entry(struct resource *res,
1754						  size_t extra_size)
1755{
1756	struct resource_entry *entry;
1757
1758	entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1759	if (entry) {
1760		INIT_LIST_HEAD(&entry->node);
1761		entry->res = res ? res : &entry->__res;
1762	}
1763
1764	return entry;
1765}
1766EXPORT_SYMBOL(resource_list_create_entry);
1767
1768void resource_list_free(struct list_head *head)
1769{
1770	struct resource_entry *entry, *tmp;
1771
1772	list_for_each_entry_safe(entry, tmp, head, node)
1773		resource_list_destroy_entry(entry);
1774}
1775EXPORT_SYMBOL(resource_list_free);
1776
1777#ifdef CONFIG_DEVICE_PRIVATE
1778static struct resource *__request_free_mem_region(struct device *dev,
1779		struct resource *base, unsigned long size, const char *name)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1780{
1781	resource_size_t end, addr;
 
 
 
 
 
 
 
 
 
 
 
 
 
1782	struct resource *res;
1783	struct region_devres *dr = NULL;
1784
1785	size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
1786	end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
1787	addr = end - size + 1UL;
1788
1789	res = alloc_resource(GFP_KERNEL);
1790	if (!res)
1791		return ERR_PTR(-ENOMEM);
1792
1793	if (dev) {
1794		dr = devres_alloc(devm_region_release,
1795				sizeof(struct region_devres), GFP_KERNEL);
1796		if (!dr) {
1797			free_resource(res);
1798			return ERR_PTR(-ENOMEM);
1799		}
 
 
 
1800	}
1801
1802	write_lock(&resource_lock);
1803	for (; addr > size && addr >= base->start; addr -= size) {
1804		if (__region_intersects(addr, size, 0, IORES_DESC_NONE) !=
1805				REGION_DISJOINT)
 
 
1806			continue;
1807
1808		if (__request_region_locked(res, &iomem_resource, addr, size,
1809						name, 0))
1810			break;
 
1811
1812		if (dev) {
1813			dr->parent = &iomem_resource;
1814			dr->start = addr;
1815			dr->n = size;
1816			devres_add(dev, dr);
1817		}
1818
1819		res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
1820		write_unlock(&resource_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1821
1822		/*
1823		 * A driver is claiming this region so revoke any mappings.
1824		 */
1825		revoke_iomem(res);
1826		return res;
1827	}
1828	write_unlock(&resource_lock);
1829
1830	free_resource(res);
1831	if (dr)
1832		devres_free(dr);
 
 
1833
1834	return ERR_PTR(-ERANGE);
1835}
1836
1837/**
1838 * devm_request_free_mem_region - find free region for device private memory
1839 *
1840 * @dev: device struct to bind the resource to
1841 * @size: size in bytes of the device memory to add
1842 * @base: resource tree to look in
1843 *
1844 * This function tries to find an empty range of physical address big enough to
1845 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1846 * memory, which in turn allocates struct pages.
1847 */
1848struct resource *devm_request_free_mem_region(struct device *dev,
1849		struct resource *base, unsigned long size)
1850{
1851	return __request_free_mem_region(dev, base, size, dev_name(dev));
 
 
 
 
1852}
1853EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
1854
1855struct resource *request_free_mem_region(struct resource *base,
1856		unsigned long size, const char *name)
1857{
1858	return __request_free_mem_region(NULL, base, size, name);
 
 
 
1859}
1860EXPORT_SYMBOL_GPL(request_free_mem_region);
1861
1862#endif /* CONFIG_DEVICE_PRIVATE */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1863
1864static int __init strict_iomem(char *str)
1865{
1866	if (strstr(str, "relaxed"))
1867		strict_iomem_checks = 0;
1868	if (strstr(str, "strict"))
1869		strict_iomem_checks = 1;
1870	return 1;
1871}
1872
1873static int iomem_fs_init_fs_context(struct fs_context *fc)
1874{
1875	return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM;
1876}
1877
1878static struct file_system_type iomem_fs_type = {
1879	.name		= "iomem",
1880	.owner		= THIS_MODULE,
1881	.init_fs_context = iomem_fs_init_fs_context,
1882	.kill_sb	= kill_anon_super,
1883};
1884
1885static int __init iomem_init_inode(void)
1886{
1887	static struct vfsmount *iomem_vfs_mount;
1888	static int iomem_fs_cnt;
1889	struct inode *inode;
1890	int rc;
1891
1892	rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt);
1893	if (rc < 0) {
1894		pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc);
1895		return rc;
1896	}
1897
1898	inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb);
1899	if (IS_ERR(inode)) {
1900		rc = PTR_ERR(inode);
1901		pr_err("Cannot allocate inode for iomem: %d\n", rc);
1902		simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt);
1903		return rc;
1904	}
1905
1906	/*
1907	 * Publish iomem revocation inode initialized.
1908	 * Pairs with smp_load_acquire() in revoke_iomem().
1909	 */
1910	smp_store_release(&iomem_inode, inode);
1911
1912	return 0;
1913}
1914
1915fs_initcall(iomem_init_inode);
1916
1917__setup("iomem=", strict_iomem);