xref: /openbmc/linux/kernel/resource.c (revision ff148d8a)
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 
29 struct resource ioport_resource = {
30 	.name	= "PCI IO",
31 	.start	= 0,
32 	.end	= IO_SPACE_LIMIT,
33 	.flags	= IORESOURCE_IO,
34 };
35 EXPORT_SYMBOL(ioport_resource);
36 
37 struct resource iomem_resource = {
38 	.name	= "PCI mem",
39 	.start	= 0,
40 	.end	= -1,
41 	.flags	= IORESOURCE_MEM,
42 };
43 EXPORT_SYMBOL(iomem_resource);
44 
45 /* constraints to be met while allocating resources */
46 struct 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 
53 static 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  */
60 static struct resource *bootmem_resource_free;
61 static DEFINE_SPINLOCK(bootmem_resource_lock);
62 
63 static 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 
76 static 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 
85 enum { MAX_IORES_LEVEL = 5 };
86 
87 static 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 
98 static void r_stop(struct seq_file *m, void *v)
99 	__releases(resource_lock)
100 {
101 	read_unlock(&resource_lock);
102 }
103 
104 static 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 
131 static const struct seq_operations resource_op = {
132 	.start	= r_start,
133 	.next	= r_next,
134 	.stop	= r_stop,
135 	.show	= r_show,
136 };
137 
138 static 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 
149 static 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 
164 static 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 */
184 static 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 
212 static 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 
241 static 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 
264 void 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  */
278 struct 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  */
295 int 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 
303 EXPORT_SYMBOL(request_resource);
304 
305 /**
306  * release_resource - release a previously reserved resource
307  * @old: resource pointer
308  */
309 int 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 
319 EXPORT_SYMBOL(release_resource);
320 
321 /**
322  * Finds the lowest iomem resource that covers part of [@start..@end].  The
323  * caller must specify @start, @end, @flags, and @desc (which may be
324  * IORES_DESC_NONE).
325  *
326  * If a resource is found, returns 0 and @*res is overwritten with the part
327  * of the resource that's within [@start..@end]; if none is found, returns
328  * -1 or -EINVAL for other invalid parameters.
329  *
330  * This function walks the whole tree and not just first level children
331  * unless @first_lvl is true.
332  *
333  * @start:	start address of the resource searched for
334  * @end:	end address of same resource
335  * @flags:	flags which the resource must have
336  * @desc:	descriptor the resource must have
337  * @first_lvl:	walk only the first level children, if set
338  * @res:	return ptr, if resource found
339  */
340 static int find_next_iomem_res(resource_size_t start, resource_size_t end,
341 			       unsigned long flags, unsigned long desc,
342 			       bool first_lvl, struct resource *res)
343 {
344 	struct resource *p;
345 
346 	if (!res)
347 		return -EINVAL;
348 
349 	if (start >= end)
350 		return -EINVAL;
351 
352 	read_lock(&resource_lock);
353 
354 	for (p = iomem_resource.child; p; p = next_resource(p, first_lvl)) {
355 		if ((p->flags & flags) != flags)
356 			continue;
357 		if ((desc != IORES_DESC_NONE) && (desc != p->desc))
358 			continue;
359 		if (p->start > end) {
360 			p = NULL;
361 			break;
362 		}
363 		if ((p->end >= start) && (p->start <= end))
364 			break;
365 	}
366 
367 	read_unlock(&resource_lock);
368 	if (!p)
369 		return -1;
370 
371 	/* copy data */
372 	res->start = max(start, p->start);
373 	res->end = min(end, p->end);
374 	res->flags = p->flags;
375 	res->desc = p->desc;
376 	return 0;
377 }
378 
379 static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
380 				 unsigned long flags, unsigned long desc,
381 				 bool first_lvl, void *arg,
382 				 int (*func)(struct resource *, void *))
383 {
384 	struct resource res;
385 	int ret = -EINVAL;
386 
387 	while (start < end &&
388 	       !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) {
389 		ret = (*func)(&res, arg);
390 		if (ret)
391 			break;
392 
393 		start = res.end + 1;
394 	}
395 
396 	return ret;
397 }
398 
399 /**
400  * Walks through iomem resources and calls func() with matching resource
401  * ranges. This walks through whole tree and not just first level children.
402  * All the memory ranges which overlap start,end and also match flags and
403  * desc are valid candidates.
404  *
405  * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
406  * @flags: I/O resource flags
407  * @start: start addr
408  * @end: end addr
409  * @arg: function argument for the callback @func
410  * @func: callback function that is called for each qualifying resource area
411  *
412  * NOTE: For a new descriptor search, define a new IORES_DESC in
413  * <linux/ioport.h> and set it in 'desc' of a target resource entry.
414  */
415 int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
416 		u64 end, void *arg, int (*func)(struct resource *, void *))
417 {
418 	return __walk_iomem_res_desc(start, end, flags, desc, false, arg, func);
419 }
420 EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
421 
422 /*
423  * This function calls the @func callback against all memory ranges of type
424  * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
425  * Now, this function is only for System RAM, it deals with full ranges and
426  * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
427  * ranges.
428  */
429 int walk_system_ram_res(u64 start, u64 end, void *arg,
430 			int (*func)(struct resource *, void *))
431 {
432 	unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
433 
434 	return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
435 				     arg, func);
436 }
437 
438 /*
439  * This function calls the @func callback against all memory ranges, which
440  * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
441  */
442 int walk_mem_res(u64 start, u64 end, void *arg,
443 		 int (*func)(struct resource *, void *))
444 {
445 	unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
446 
447 	return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
448 				     arg, func);
449 }
450 
451 /*
452  * This function calls the @func callback against all memory ranges of type
453  * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
454  * It is to be used only for System RAM.
455  *
456  * This will find System RAM ranges that are children of top-level resources
457  * in addition to top-level System RAM resources.
458  */
459 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
460 			  void *arg, int (*func)(unsigned long, unsigned long, void *))
461 {
462 	resource_size_t start, end;
463 	unsigned long flags;
464 	struct resource res;
465 	unsigned long pfn, end_pfn;
466 	int ret = -EINVAL;
467 
468 	start = (u64) start_pfn << PAGE_SHIFT;
469 	end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
470 	flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
471 	while (start < end &&
472 	       !find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
473 				    false, &res)) {
474 		pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
475 		end_pfn = (res.end + 1) >> PAGE_SHIFT;
476 		if (end_pfn > pfn)
477 			ret = (*func)(pfn, end_pfn - pfn, arg);
478 		if (ret)
479 			break;
480 		start = res.end + 1;
481 	}
482 	return ret;
483 }
484 
485 static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
486 {
487 	return 1;
488 }
489 
490 /*
491  * This generic page_is_ram() returns true if specified address is
492  * registered as System RAM in iomem_resource list.
493  */
494 int __weak page_is_ram(unsigned long pfn)
495 {
496 	return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
497 }
498 EXPORT_SYMBOL_GPL(page_is_ram);
499 
500 /**
501  * region_intersects() - determine intersection of region with known resources
502  * @start: region start address
503  * @size: size of region
504  * @flags: flags of resource (in iomem_resource)
505  * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
506  *
507  * Check if the specified region partially overlaps or fully eclipses a
508  * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
509  * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
510  * return REGION_MIXED if the region overlaps @flags/@desc and another
511  * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
512  * and no other defined resource. Note that REGION_INTERSECTS is also
513  * returned in the case when the specified region overlaps RAM and undefined
514  * memory holes.
515  *
516  * region_intersect() is used by memory remapping functions to ensure
517  * the user is not remapping RAM and is a vast speed up over walking
518  * through the resource table page by page.
519  */
520 int region_intersects(resource_size_t start, size_t size, unsigned long flags,
521 		      unsigned long desc)
522 {
523 	struct resource res;
524 	int type = 0; int other = 0;
525 	struct resource *p;
526 
527 	res.start = start;
528 	res.end = start + size - 1;
529 
530 	read_lock(&resource_lock);
531 	for (p = iomem_resource.child; p ; p = p->sibling) {
532 		bool is_type = (((p->flags & flags) == flags) &&
533 				((desc == IORES_DESC_NONE) ||
534 				 (desc == p->desc)));
535 
536 		if (resource_overlaps(p, &res))
537 			is_type ? type++ : other++;
538 	}
539 	read_unlock(&resource_lock);
540 
541 	if (other == 0)
542 		return type ? REGION_INTERSECTS : REGION_DISJOINT;
543 
544 	if (type)
545 		return REGION_MIXED;
546 
547 	return REGION_DISJOINT;
548 }
549 EXPORT_SYMBOL_GPL(region_intersects);
550 
551 void __weak arch_remove_reservations(struct resource *avail)
552 {
553 }
554 
555 static resource_size_t simple_align_resource(void *data,
556 					     const struct resource *avail,
557 					     resource_size_t size,
558 					     resource_size_t align)
559 {
560 	return avail->start;
561 }
562 
563 static void resource_clip(struct resource *res, resource_size_t min,
564 			  resource_size_t max)
565 {
566 	if (res->start < min)
567 		res->start = min;
568 	if (res->end > max)
569 		res->end = max;
570 }
571 
572 /*
573  * Find empty slot in the resource tree with the given range and
574  * alignment constraints
575  */
576 static int __find_resource(struct resource *root, struct resource *old,
577 			 struct resource *new,
578 			 resource_size_t  size,
579 			 struct resource_constraint *constraint)
580 {
581 	struct resource *this = root->child;
582 	struct resource tmp = *new, avail, alloc;
583 
584 	tmp.start = root->start;
585 	/*
586 	 * Skip past an allocated resource that starts at 0, since the assignment
587 	 * of this->start - 1 to tmp->end below would cause an underflow.
588 	 */
589 	if (this && this->start == root->start) {
590 		tmp.start = (this == old) ? old->start : this->end + 1;
591 		this = this->sibling;
592 	}
593 	for(;;) {
594 		if (this)
595 			tmp.end = (this == old) ?  this->end : this->start - 1;
596 		else
597 			tmp.end = root->end;
598 
599 		if (tmp.end < tmp.start)
600 			goto next;
601 
602 		resource_clip(&tmp, constraint->min, constraint->max);
603 		arch_remove_reservations(&tmp);
604 
605 		/* Check for overflow after ALIGN() */
606 		avail.start = ALIGN(tmp.start, constraint->align);
607 		avail.end = tmp.end;
608 		avail.flags = new->flags & ~IORESOURCE_UNSET;
609 		if (avail.start >= tmp.start) {
610 			alloc.flags = avail.flags;
611 			alloc.start = constraint->alignf(constraint->alignf_data, &avail,
612 					size, constraint->align);
613 			alloc.end = alloc.start + size - 1;
614 			if (alloc.start <= alloc.end &&
615 			    resource_contains(&avail, &alloc)) {
616 				new->start = alloc.start;
617 				new->end = alloc.end;
618 				return 0;
619 			}
620 		}
621 
622 next:		if (!this || this->end == root->end)
623 			break;
624 
625 		if (this != old)
626 			tmp.start = this->end + 1;
627 		this = this->sibling;
628 	}
629 	return -EBUSY;
630 }
631 
632 /*
633  * Find empty slot in the resource tree given range and alignment.
634  */
635 static int find_resource(struct resource *root, struct resource *new,
636 			resource_size_t size,
637 			struct resource_constraint  *constraint)
638 {
639 	return  __find_resource(root, NULL, new, size, constraint);
640 }
641 
642 /**
643  * reallocate_resource - allocate a slot in the resource tree given range & alignment.
644  *	The resource will be relocated if the new size cannot be reallocated in the
645  *	current location.
646  *
647  * @root: root resource descriptor
648  * @old:  resource descriptor desired by caller
649  * @newsize: new size of the resource descriptor
650  * @constraint: the size and alignment constraints to be met.
651  */
652 static int reallocate_resource(struct resource *root, struct resource *old,
653 			       resource_size_t newsize,
654 			       struct resource_constraint *constraint)
655 {
656 	int err=0;
657 	struct resource new = *old;
658 	struct resource *conflict;
659 
660 	write_lock(&resource_lock);
661 
662 	if ((err = __find_resource(root, old, &new, newsize, constraint)))
663 		goto out;
664 
665 	if (resource_contains(&new, old)) {
666 		old->start = new.start;
667 		old->end = new.end;
668 		goto out;
669 	}
670 
671 	if (old->child) {
672 		err = -EBUSY;
673 		goto out;
674 	}
675 
676 	if (resource_contains(old, &new)) {
677 		old->start = new.start;
678 		old->end = new.end;
679 	} else {
680 		__release_resource(old, true);
681 		*old = new;
682 		conflict = __request_resource(root, old);
683 		BUG_ON(conflict);
684 	}
685 out:
686 	write_unlock(&resource_lock);
687 	return err;
688 }
689 
690 
691 /**
692  * allocate_resource - allocate empty slot in the resource tree given range & alignment.
693  * 	The resource will be reallocated with a new size if it was already allocated
694  * @root: root resource descriptor
695  * @new: resource descriptor desired by caller
696  * @size: requested resource region size
697  * @min: minimum boundary to allocate
698  * @max: maximum boundary to allocate
699  * @align: alignment requested, in bytes
700  * @alignf: alignment function, optional, called if not NULL
701  * @alignf_data: arbitrary data to pass to the @alignf function
702  */
703 int allocate_resource(struct resource *root, struct resource *new,
704 		      resource_size_t size, resource_size_t min,
705 		      resource_size_t max, resource_size_t align,
706 		      resource_size_t (*alignf)(void *,
707 						const struct resource *,
708 						resource_size_t,
709 						resource_size_t),
710 		      void *alignf_data)
711 {
712 	int err;
713 	struct resource_constraint constraint;
714 
715 	if (!alignf)
716 		alignf = simple_align_resource;
717 
718 	constraint.min = min;
719 	constraint.max = max;
720 	constraint.align = align;
721 	constraint.alignf = alignf;
722 	constraint.alignf_data = alignf_data;
723 
724 	if ( new->parent ) {
725 		/* resource is already allocated, try reallocating with
726 		   the new constraints */
727 		return reallocate_resource(root, new, size, &constraint);
728 	}
729 
730 	write_lock(&resource_lock);
731 	err = find_resource(root, new, size, &constraint);
732 	if (err >= 0 && __request_resource(root, new))
733 		err = -EBUSY;
734 	write_unlock(&resource_lock);
735 	return err;
736 }
737 
738 EXPORT_SYMBOL(allocate_resource);
739 
740 /**
741  * lookup_resource - find an existing resource by a resource start address
742  * @root: root resource descriptor
743  * @start: resource start address
744  *
745  * Returns a pointer to the resource if found, NULL otherwise
746  */
747 struct resource *lookup_resource(struct resource *root, resource_size_t start)
748 {
749 	struct resource *res;
750 
751 	read_lock(&resource_lock);
752 	for (res = root->child; res; res = res->sibling) {
753 		if (res->start == start)
754 			break;
755 	}
756 	read_unlock(&resource_lock);
757 
758 	return res;
759 }
760 
761 /*
762  * Insert a resource into the resource tree. If successful, return NULL,
763  * otherwise return the conflicting resource (compare to __request_resource())
764  */
765 static struct resource * __insert_resource(struct resource *parent, struct resource *new)
766 {
767 	struct resource *first, *next;
768 
769 	for (;; parent = first) {
770 		first = __request_resource(parent, new);
771 		if (!first)
772 			return first;
773 
774 		if (first == parent)
775 			return first;
776 		if (WARN_ON(first == new))	/* duplicated insertion */
777 			return first;
778 
779 		if ((first->start > new->start) || (first->end < new->end))
780 			break;
781 		if ((first->start == new->start) && (first->end == new->end))
782 			break;
783 	}
784 
785 	for (next = first; ; next = next->sibling) {
786 		/* Partial overlap? Bad, and unfixable */
787 		if (next->start < new->start || next->end > new->end)
788 			return next;
789 		if (!next->sibling)
790 			break;
791 		if (next->sibling->start > new->end)
792 			break;
793 	}
794 
795 	new->parent = parent;
796 	new->sibling = next->sibling;
797 	new->child = first;
798 
799 	next->sibling = NULL;
800 	for (next = first; next; next = next->sibling)
801 		next->parent = new;
802 
803 	if (parent->child == first) {
804 		parent->child = new;
805 	} else {
806 		next = parent->child;
807 		while (next->sibling != first)
808 			next = next->sibling;
809 		next->sibling = new;
810 	}
811 	return NULL;
812 }
813 
814 /**
815  * insert_resource_conflict - Inserts resource in the resource tree
816  * @parent: parent of the new resource
817  * @new: new resource to insert
818  *
819  * Returns 0 on success, conflict resource if the resource can't be inserted.
820  *
821  * This function is equivalent to request_resource_conflict when no conflict
822  * happens. If a conflict happens, and the conflicting resources
823  * entirely fit within the range of the new resource, then the new
824  * resource is inserted and the conflicting resources become children of
825  * the new resource.
826  *
827  * This function is intended for producers of resources, such as FW modules
828  * and bus drivers.
829  */
830 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
831 {
832 	struct resource *conflict;
833 
834 	write_lock(&resource_lock);
835 	conflict = __insert_resource(parent, new);
836 	write_unlock(&resource_lock);
837 	return conflict;
838 }
839 
840 /**
841  * insert_resource - Inserts a resource in the resource tree
842  * @parent: parent of the new resource
843  * @new: new resource to insert
844  *
845  * Returns 0 on success, -EBUSY if the resource can't be inserted.
846  *
847  * This function is intended for producers of resources, such as FW modules
848  * and bus drivers.
849  */
850 int insert_resource(struct resource *parent, struct resource *new)
851 {
852 	struct resource *conflict;
853 
854 	conflict = insert_resource_conflict(parent, new);
855 	return conflict ? -EBUSY : 0;
856 }
857 EXPORT_SYMBOL_GPL(insert_resource);
858 
859 /**
860  * insert_resource_expand_to_fit - Insert a resource into the resource tree
861  * @root: root resource descriptor
862  * @new: new resource to insert
863  *
864  * Insert a resource into the resource tree, possibly expanding it in order
865  * to make it encompass any conflicting resources.
866  */
867 void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
868 {
869 	if (new->parent)
870 		return;
871 
872 	write_lock(&resource_lock);
873 	for (;;) {
874 		struct resource *conflict;
875 
876 		conflict = __insert_resource(root, new);
877 		if (!conflict)
878 			break;
879 		if (conflict == root)
880 			break;
881 
882 		/* Ok, expand resource to cover the conflict, then try again .. */
883 		if (conflict->start < new->start)
884 			new->start = conflict->start;
885 		if (conflict->end > new->end)
886 			new->end = conflict->end;
887 
888 		printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
889 	}
890 	write_unlock(&resource_lock);
891 }
892 
893 /**
894  * remove_resource - Remove a resource in the resource tree
895  * @old: resource to remove
896  *
897  * Returns 0 on success, -EINVAL if the resource is not valid.
898  *
899  * This function removes a resource previously inserted by insert_resource()
900  * or insert_resource_conflict(), and moves the children (if any) up to
901  * where they were before.  insert_resource() and insert_resource_conflict()
902  * insert a new resource, and move any conflicting resources down to the
903  * children of the new resource.
904  *
905  * insert_resource(), insert_resource_conflict() and remove_resource() are
906  * intended for producers of resources, such as FW modules and bus drivers.
907  */
908 int remove_resource(struct resource *old)
909 {
910 	int retval;
911 
912 	write_lock(&resource_lock);
913 	retval = __release_resource(old, false);
914 	write_unlock(&resource_lock);
915 	return retval;
916 }
917 EXPORT_SYMBOL_GPL(remove_resource);
918 
919 static int __adjust_resource(struct resource *res, resource_size_t start,
920 				resource_size_t size)
921 {
922 	struct resource *tmp, *parent = res->parent;
923 	resource_size_t end = start + size - 1;
924 	int result = -EBUSY;
925 
926 	if (!parent)
927 		goto skip;
928 
929 	if ((start < parent->start) || (end > parent->end))
930 		goto out;
931 
932 	if (res->sibling && (res->sibling->start <= end))
933 		goto out;
934 
935 	tmp = parent->child;
936 	if (tmp != res) {
937 		while (tmp->sibling != res)
938 			tmp = tmp->sibling;
939 		if (start <= tmp->end)
940 			goto out;
941 	}
942 
943 skip:
944 	for (tmp = res->child; tmp; tmp = tmp->sibling)
945 		if ((tmp->start < start) || (tmp->end > end))
946 			goto out;
947 
948 	res->start = start;
949 	res->end = end;
950 	result = 0;
951 
952  out:
953 	return result;
954 }
955 
956 /**
957  * adjust_resource - modify a resource's start and size
958  * @res: resource to modify
959  * @start: new start value
960  * @size: new size
961  *
962  * Given an existing resource, change its start and size to match the
963  * arguments.  Returns 0 on success, -EBUSY if it can't fit.
964  * Existing children of the resource are assumed to be immutable.
965  */
966 int adjust_resource(struct resource *res, resource_size_t start,
967 		    resource_size_t size)
968 {
969 	int result;
970 
971 	write_lock(&resource_lock);
972 	result = __adjust_resource(res, start, size);
973 	write_unlock(&resource_lock);
974 	return result;
975 }
976 EXPORT_SYMBOL(adjust_resource);
977 
978 static void __init
979 __reserve_region_with_split(struct resource *root, resource_size_t start,
980 			    resource_size_t end, const char *name)
981 {
982 	struct resource *parent = root;
983 	struct resource *conflict;
984 	struct resource *res = alloc_resource(GFP_ATOMIC);
985 	struct resource *next_res = NULL;
986 	int type = resource_type(root);
987 
988 	if (!res)
989 		return;
990 
991 	res->name = name;
992 	res->start = start;
993 	res->end = end;
994 	res->flags = type | IORESOURCE_BUSY;
995 	res->desc = IORES_DESC_NONE;
996 
997 	while (1) {
998 
999 		conflict = __request_resource(parent, res);
1000 		if (!conflict) {
1001 			if (!next_res)
1002 				break;
1003 			res = next_res;
1004 			next_res = NULL;
1005 			continue;
1006 		}
1007 
1008 		/* conflict covered whole area */
1009 		if (conflict->start <= res->start &&
1010 				conflict->end >= res->end) {
1011 			free_resource(res);
1012 			WARN_ON(next_res);
1013 			break;
1014 		}
1015 
1016 		/* failed, split and try again */
1017 		if (conflict->start > res->start) {
1018 			end = res->end;
1019 			res->end = conflict->start - 1;
1020 			if (conflict->end < end) {
1021 				next_res = alloc_resource(GFP_ATOMIC);
1022 				if (!next_res) {
1023 					free_resource(res);
1024 					break;
1025 				}
1026 				next_res->name = name;
1027 				next_res->start = conflict->end + 1;
1028 				next_res->end = end;
1029 				next_res->flags = type | IORESOURCE_BUSY;
1030 				next_res->desc = IORES_DESC_NONE;
1031 			}
1032 		} else {
1033 			res->start = conflict->end + 1;
1034 		}
1035 	}
1036 
1037 }
1038 
1039 void __init
1040 reserve_region_with_split(struct resource *root, resource_size_t start,
1041 			  resource_size_t end, const char *name)
1042 {
1043 	int abort = 0;
1044 
1045 	write_lock(&resource_lock);
1046 	if (root->start > start || root->end < end) {
1047 		pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1048 		       (unsigned long long)start, (unsigned long long)end,
1049 		       root);
1050 		if (start > root->end || end < root->start)
1051 			abort = 1;
1052 		else {
1053 			if (end > root->end)
1054 				end = root->end;
1055 			if (start < root->start)
1056 				start = root->start;
1057 			pr_err("fixing request to [0x%llx-0x%llx]\n",
1058 			       (unsigned long long)start,
1059 			       (unsigned long long)end);
1060 		}
1061 		dump_stack();
1062 	}
1063 	if (!abort)
1064 		__reserve_region_with_split(root, start, end, name);
1065 	write_unlock(&resource_lock);
1066 }
1067 
1068 /**
1069  * resource_alignment - calculate resource's alignment
1070  * @res: resource pointer
1071  *
1072  * Returns alignment on success, 0 (invalid alignment) on failure.
1073  */
1074 resource_size_t resource_alignment(struct resource *res)
1075 {
1076 	switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1077 	case IORESOURCE_SIZEALIGN:
1078 		return resource_size(res);
1079 	case IORESOURCE_STARTALIGN:
1080 		return res->start;
1081 	default:
1082 		return 0;
1083 	}
1084 }
1085 
1086 /*
1087  * This is compatibility stuff for IO resources.
1088  *
1089  * Note how this, unlike the above, knows about
1090  * the IO flag meanings (busy etc).
1091  *
1092  * request_region creates a new busy region.
1093  *
1094  * release_region releases a matching busy region.
1095  */
1096 
1097 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1098 
1099 /**
1100  * __request_region - create a new busy resource region
1101  * @parent: parent resource descriptor
1102  * @start: resource start address
1103  * @n: resource region size
1104  * @name: reserving caller's ID string
1105  * @flags: IO resource flags
1106  */
1107 struct resource * __request_region(struct resource *parent,
1108 				   resource_size_t start, resource_size_t n,
1109 				   const char *name, int flags)
1110 {
1111 	DECLARE_WAITQUEUE(wait, current);
1112 	struct resource *res = alloc_resource(GFP_KERNEL);
1113 
1114 	if (!res)
1115 		return NULL;
1116 
1117 	res->name = name;
1118 	res->start = start;
1119 	res->end = start + n - 1;
1120 
1121 	write_lock(&resource_lock);
1122 
1123 	for (;;) {
1124 		struct resource *conflict;
1125 
1126 		res->flags = resource_type(parent) | resource_ext_type(parent);
1127 		res->flags |= IORESOURCE_BUSY | flags;
1128 		res->desc = parent->desc;
1129 
1130 		conflict = __request_resource(parent, res);
1131 		if (!conflict)
1132 			break;
1133 		/*
1134 		 * mm/hmm.c reserves physical addresses which then
1135 		 * become unavailable to other users.  Conflicts are
1136 		 * not expected.  Warn to aid debugging if encountered.
1137 		 */
1138 		if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1139 			pr_warn("Unaddressable device %s %pR conflicts with %pR",
1140 				conflict->name, conflict, res);
1141 		}
1142 		if (conflict != parent) {
1143 			if (!(conflict->flags & IORESOURCE_BUSY)) {
1144 				parent = conflict;
1145 				continue;
1146 			}
1147 		}
1148 		if (conflict->flags & flags & IORESOURCE_MUXED) {
1149 			add_wait_queue(&muxed_resource_wait, &wait);
1150 			write_unlock(&resource_lock);
1151 			set_current_state(TASK_UNINTERRUPTIBLE);
1152 			schedule();
1153 			remove_wait_queue(&muxed_resource_wait, &wait);
1154 			write_lock(&resource_lock);
1155 			continue;
1156 		}
1157 		/* Uhhuh, that didn't work out.. */
1158 		free_resource(res);
1159 		res = NULL;
1160 		break;
1161 	}
1162 	write_unlock(&resource_lock);
1163 	return res;
1164 }
1165 EXPORT_SYMBOL(__request_region);
1166 
1167 /**
1168  * __release_region - release a previously reserved resource region
1169  * @parent: parent resource descriptor
1170  * @start: resource start address
1171  * @n: resource region size
1172  *
1173  * The described resource region must match a currently busy region.
1174  */
1175 void __release_region(struct resource *parent, resource_size_t start,
1176 		      resource_size_t n)
1177 {
1178 	struct resource **p;
1179 	resource_size_t end;
1180 
1181 	p = &parent->child;
1182 	end = start + n - 1;
1183 
1184 	write_lock(&resource_lock);
1185 
1186 	for (;;) {
1187 		struct resource *res = *p;
1188 
1189 		if (!res)
1190 			break;
1191 		if (res->start <= start && res->end >= end) {
1192 			if (!(res->flags & IORESOURCE_BUSY)) {
1193 				p = &res->child;
1194 				continue;
1195 			}
1196 			if (res->start != start || res->end != end)
1197 				break;
1198 			*p = res->sibling;
1199 			write_unlock(&resource_lock);
1200 			if (res->flags & IORESOURCE_MUXED)
1201 				wake_up(&muxed_resource_wait);
1202 			free_resource(res);
1203 			return;
1204 		}
1205 		p = &res->sibling;
1206 	}
1207 
1208 	write_unlock(&resource_lock);
1209 
1210 	printk(KERN_WARNING "Trying to free nonexistent resource "
1211 		"<%016llx-%016llx>\n", (unsigned long long)start,
1212 		(unsigned long long)end);
1213 }
1214 EXPORT_SYMBOL(__release_region);
1215 
1216 #ifdef CONFIG_MEMORY_HOTREMOVE
1217 /**
1218  * release_mem_region_adjustable - release a previously reserved memory region
1219  * @parent: parent resource descriptor
1220  * @start: resource start address
1221  * @size: resource region size
1222  *
1223  * This interface is intended for memory hot-delete.  The requested region
1224  * is released from a currently busy memory resource.  The requested region
1225  * must either match exactly or fit into a single busy resource entry.  In
1226  * the latter case, the remaining resource is adjusted accordingly.
1227  * Existing children of the busy memory resource must be immutable in the
1228  * request.
1229  *
1230  * Note:
1231  * - Additional release conditions, such as overlapping region, can be
1232  *   supported after they are confirmed as valid cases.
1233  * - When a busy memory resource gets split into two entries, the code
1234  *   assumes that all children remain in the lower address entry for
1235  *   simplicity.  Enhance this logic when necessary.
1236  */
1237 int release_mem_region_adjustable(struct resource *parent,
1238 				  resource_size_t start, resource_size_t size)
1239 {
1240 	struct resource **p;
1241 	struct resource *res;
1242 	struct resource *new_res;
1243 	resource_size_t end;
1244 	int ret = -EINVAL;
1245 
1246 	end = start + size - 1;
1247 	if ((start < parent->start) || (end > parent->end))
1248 		return ret;
1249 
1250 	/* The alloc_resource() result gets checked later */
1251 	new_res = alloc_resource(GFP_KERNEL);
1252 
1253 	p = &parent->child;
1254 	write_lock(&resource_lock);
1255 
1256 	while ((res = *p)) {
1257 		if (res->start >= end)
1258 			break;
1259 
1260 		/* look for the next resource if it does not fit into */
1261 		if (res->start > start || res->end < end) {
1262 			p = &res->sibling;
1263 			continue;
1264 		}
1265 
1266 		/*
1267 		 * All memory regions added from memory-hotplug path have the
1268 		 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1269 		 * this flag, we know that we are dealing with a resource coming
1270 		 * from HMM/devm. HMM/devm use another mechanism to add/release
1271 		 * a resource. This goes via devm_request_mem_region and
1272 		 * devm_release_mem_region.
1273 		 * HMM/devm take care to release their resources when they want,
1274 		 * so if we are dealing with them, let us just back off here.
1275 		 */
1276 		if (!(res->flags & IORESOURCE_SYSRAM)) {
1277 			ret = 0;
1278 			break;
1279 		}
1280 
1281 		if (!(res->flags & IORESOURCE_MEM))
1282 			break;
1283 
1284 		if (!(res->flags & IORESOURCE_BUSY)) {
1285 			p = &res->child;
1286 			continue;
1287 		}
1288 
1289 		/* found the target resource; let's adjust accordingly */
1290 		if (res->start == start && res->end == end) {
1291 			/* free the whole entry */
1292 			*p = res->sibling;
1293 			free_resource(res);
1294 			ret = 0;
1295 		} else if (res->start == start && res->end != end) {
1296 			/* adjust the start */
1297 			ret = __adjust_resource(res, end + 1,
1298 						res->end - end);
1299 		} else if (res->start != start && res->end == end) {
1300 			/* adjust the end */
1301 			ret = __adjust_resource(res, res->start,
1302 						start - res->start);
1303 		} else {
1304 			/* split into two entries */
1305 			if (!new_res) {
1306 				ret = -ENOMEM;
1307 				break;
1308 			}
1309 			new_res->name = res->name;
1310 			new_res->start = end + 1;
1311 			new_res->end = res->end;
1312 			new_res->flags = res->flags;
1313 			new_res->desc = res->desc;
1314 			new_res->parent = res->parent;
1315 			new_res->sibling = res->sibling;
1316 			new_res->child = NULL;
1317 
1318 			ret = __adjust_resource(res, res->start,
1319 						start - res->start);
1320 			if (ret)
1321 				break;
1322 			res->sibling = new_res;
1323 			new_res = NULL;
1324 		}
1325 
1326 		break;
1327 	}
1328 
1329 	write_unlock(&resource_lock);
1330 	free_resource(new_res);
1331 	return ret;
1332 }
1333 #endif	/* CONFIG_MEMORY_HOTREMOVE */
1334 
1335 /*
1336  * Managed region resource
1337  */
1338 static void devm_resource_release(struct device *dev, void *ptr)
1339 {
1340 	struct resource **r = ptr;
1341 
1342 	release_resource(*r);
1343 }
1344 
1345 /**
1346  * devm_request_resource() - request and reserve an I/O or memory resource
1347  * @dev: device for which to request the resource
1348  * @root: root of the resource tree from which to request the resource
1349  * @new: descriptor of the resource to request
1350  *
1351  * This is a device-managed version of request_resource(). There is usually
1352  * no need to release resources requested by this function explicitly since
1353  * that will be taken care of when the device is unbound from its driver.
1354  * If for some reason the resource needs to be released explicitly, because
1355  * of ordering issues for example, drivers must call devm_release_resource()
1356  * rather than the regular release_resource().
1357  *
1358  * When a conflict is detected between any existing resources and the newly
1359  * requested resource, an error message will be printed.
1360  *
1361  * Returns 0 on success or a negative error code on failure.
1362  */
1363 int devm_request_resource(struct device *dev, struct resource *root,
1364 			  struct resource *new)
1365 {
1366 	struct resource *conflict, **ptr;
1367 
1368 	ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1369 	if (!ptr)
1370 		return -ENOMEM;
1371 
1372 	*ptr = new;
1373 
1374 	conflict = request_resource_conflict(root, new);
1375 	if (conflict) {
1376 		dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1377 			new, conflict->name, conflict);
1378 		devres_free(ptr);
1379 		return -EBUSY;
1380 	}
1381 
1382 	devres_add(dev, ptr);
1383 	return 0;
1384 }
1385 EXPORT_SYMBOL(devm_request_resource);
1386 
1387 static int devm_resource_match(struct device *dev, void *res, void *data)
1388 {
1389 	struct resource **ptr = res;
1390 
1391 	return *ptr == data;
1392 }
1393 
1394 /**
1395  * devm_release_resource() - release a previously requested resource
1396  * @dev: device for which to release the resource
1397  * @new: descriptor of the resource to release
1398  *
1399  * Releases a resource previously requested using devm_request_resource().
1400  */
1401 void devm_release_resource(struct device *dev, struct resource *new)
1402 {
1403 	WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1404 			       new));
1405 }
1406 EXPORT_SYMBOL(devm_release_resource);
1407 
1408 struct region_devres {
1409 	struct resource *parent;
1410 	resource_size_t start;
1411 	resource_size_t n;
1412 };
1413 
1414 static void devm_region_release(struct device *dev, void *res)
1415 {
1416 	struct region_devres *this = res;
1417 
1418 	__release_region(this->parent, this->start, this->n);
1419 }
1420 
1421 static int devm_region_match(struct device *dev, void *res, void *match_data)
1422 {
1423 	struct region_devres *this = res, *match = match_data;
1424 
1425 	return this->parent == match->parent &&
1426 		this->start == match->start && this->n == match->n;
1427 }
1428 
1429 struct resource *
1430 __devm_request_region(struct device *dev, struct resource *parent,
1431 		      resource_size_t start, resource_size_t n, const char *name)
1432 {
1433 	struct region_devres *dr = NULL;
1434 	struct resource *res;
1435 
1436 	dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1437 			  GFP_KERNEL);
1438 	if (!dr)
1439 		return NULL;
1440 
1441 	dr->parent = parent;
1442 	dr->start = start;
1443 	dr->n = n;
1444 
1445 	res = __request_region(parent, start, n, name, 0);
1446 	if (res)
1447 		devres_add(dev, dr);
1448 	else
1449 		devres_free(dr);
1450 
1451 	return res;
1452 }
1453 EXPORT_SYMBOL(__devm_request_region);
1454 
1455 void __devm_release_region(struct device *dev, struct resource *parent,
1456 			   resource_size_t start, resource_size_t n)
1457 {
1458 	struct region_devres match_data = { parent, start, n };
1459 
1460 	__release_region(parent, start, n);
1461 	WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1462 			       &match_data));
1463 }
1464 EXPORT_SYMBOL(__devm_release_region);
1465 
1466 /*
1467  * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1468  */
1469 #define MAXRESERVE 4
1470 static int __init reserve_setup(char *str)
1471 {
1472 	static int reserved;
1473 	static struct resource reserve[MAXRESERVE];
1474 
1475 	for (;;) {
1476 		unsigned int io_start, io_num;
1477 		int x = reserved;
1478 		struct resource *parent;
1479 
1480 		if (get_option(&str, &io_start) != 2)
1481 			break;
1482 		if (get_option(&str, &io_num) == 0)
1483 			break;
1484 		if (x < MAXRESERVE) {
1485 			struct resource *res = reserve + x;
1486 
1487 			/*
1488 			 * If the region starts below 0x10000, we assume it's
1489 			 * I/O port space; otherwise assume it's memory.
1490 			 */
1491 			if (io_start < 0x10000) {
1492 				res->flags = IORESOURCE_IO;
1493 				parent = &ioport_resource;
1494 			} else {
1495 				res->flags = IORESOURCE_MEM;
1496 				parent = &iomem_resource;
1497 			}
1498 			res->name = "reserved";
1499 			res->start = io_start;
1500 			res->end = io_start + io_num - 1;
1501 			res->flags |= IORESOURCE_BUSY;
1502 			res->desc = IORES_DESC_NONE;
1503 			res->child = NULL;
1504 			if (request_resource(parent, res) == 0)
1505 				reserved = x+1;
1506 		}
1507 	}
1508 	return 1;
1509 }
1510 __setup("reserve=", reserve_setup);
1511 
1512 /*
1513  * Check if the requested addr and size spans more than any slot in the
1514  * iomem resource tree.
1515  */
1516 int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1517 {
1518 	struct resource *p = &iomem_resource;
1519 	int err = 0;
1520 	loff_t l;
1521 
1522 	read_lock(&resource_lock);
1523 	for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1524 		/*
1525 		 * We can probably skip the resources without
1526 		 * IORESOURCE_IO attribute?
1527 		 */
1528 		if (p->start >= addr + size)
1529 			continue;
1530 		if (p->end < addr)
1531 			continue;
1532 		if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1533 		    PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1534 			continue;
1535 		/*
1536 		 * if a resource is "BUSY", it's not a hardware resource
1537 		 * but a driver mapping of such a resource; we don't want
1538 		 * to warn for those; some drivers legitimately map only
1539 		 * partial hardware resources. (example: vesafb)
1540 		 */
1541 		if (p->flags & IORESOURCE_BUSY)
1542 			continue;
1543 
1544 		printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1545 		       (unsigned long long)addr,
1546 		       (unsigned long long)(addr + size - 1),
1547 		       p->name, p);
1548 		err = -1;
1549 		break;
1550 	}
1551 	read_unlock(&resource_lock);
1552 
1553 	return err;
1554 }
1555 
1556 #ifdef CONFIG_STRICT_DEVMEM
1557 static int strict_iomem_checks = 1;
1558 #else
1559 static int strict_iomem_checks;
1560 #endif
1561 
1562 /*
1563  * check if an address is reserved in the iomem resource tree
1564  * returns true if reserved, false if not reserved.
1565  */
1566 bool iomem_is_exclusive(u64 addr)
1567 {
1568 	struct resource *p = &iomem_resource;
1569 	bool err = false;
1570 	loff_t l;
1571 	int size = PAGE_SIZE;
1572 
1573 	if (!strict_iomem_checks)
1574 		return false;
1575 
1576 	addr = addr & PAGE_MASK;
1577 
1578 	read_lock(&resource_lock);
1579 	for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1580 		/*
1581 		 * We can probably skip the resources without
1582 		 * IORESOURCE_IO attribute?
1583 		 */
1584 		if (p->start >= addr + size)
1585 			break;
1586 		if (p->end < addr)
1587 			continue;
1588 		/*
1589 		 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1590 		 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1591 		 * resource is busy.
1592 		 */
1593 		if ((p->flags & IORESOURCE_BUSY) == 0)
1594 			continue;
1595 		if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1596 				|| p->flags & IORESOURCE_EXCLUSIVE) {
1597 			err = true;
1598 			break;
1599 		}
1600 	}
1601 	read_unlock(&resource_lock);
1602 
1603 	return err;
1604 }
1605 
1606 struct resource_entry *resource_list_create_entry(struct resource *res,
1607 						  size_t extra_size)
1608 {
1609 	struct resource_entry *entry;
1610 
1611 	entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1612 	if (entry) {
1613 		INIT_LIST_HEAD(&entry->node);
1614 		entry->res = res ? res : &entry->__res;
1615 	}
1616 
1617 	return entry;
1618 }
1619 EXPORT_SYMBOL(resource_list_create_entry);
1620 
1621 void resource_list_free(struct list_head *head)
1622 {
1623 	struct resource_entry *entry, *tmp;
1624 
1625 	list_for_each_entry_safe(entry, tmp, head, node)
1626 		resource_list_destroy_entry(entry);
1627 }
1628 EXPORT_SYMBOL(resource_list_free);
1629 
1630 static int __init strict_iomem(char *str)
1631 {
1632 	if (strstr(str, "relaxed"))
1633 		strict_iomem_checks = 0;
1634 	if (strstr(str, "strict"))
1635 		strict_iomem_checks = 1;
1636 	return 1;
1637 }
1638 
1639 __setup("iomem=", strict_iomem);
1640