projects/linux·blob v5.8-rc5 · refs

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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 <[email protected]>
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/sched.h>
22#include <linux/seq_file.h>
23#include <linux/device.h>
24#include <linux/pfn.h>
25#include <linux/mm.h>
26#include <linux/resource_ext.h>
27#include <asm/io.h>
28
29
30struct resource ioport_resource = {
31 .name = "PCI IO",
32 .start = 0,
33 .end = IO_SPACE_LIMIT,
34 .flags = IORESOURCE_IO,
35};
36EXPORT_SYMBOL(ioport_resource);
37
38struct resource iomem_resource = {
39 .name = "PCI mem",
40 .start = 0,
41 .end = -1,
42 .flags = IORESOURCE_MEM,
43};
44EXPORT_SYMBOL(iomem_resource);
45
46/* constraints to be met while allocating resources */
47struct resource_constraint {
48 resource_size_t min, max, align;
49 resource_size_t (*alignf)(void *, const struct resource *,
50 resource_size_t, resource_size_t);
51 void *alignf_data;
52};
53
54static DEFINE_RWLOCK(resource_lock);
55
56/*
57 * For memory hotplug, there is no way to free resource entries allocated
58 * by boot mem after the system is up. So for reusing the resource entry
59 * we need to remember the resource.
60 */
61static struct resource *bootmem_resource_free;
62static DEFINE_SPINLOCK(bootmem_resource_lock);
63
64static struct resource *next_resource(struct resource *p, bool sibling_only)
65{
66 /* Caller wants to traverse through siblings only */
67 if (sibling_only)
68 return p->sibling;
69
70 if (p->child)
71 return p->child;
72 while (!p->sibling && p->parent)
73 p = p->parent;
74 return p->sibling;
75}
76
77static void *r_next(struct seq_file *m, void *v, loff_t *pos)
78{
79 struct resource *p = v;
80 (*pos)++;
81 return (void *)next_resource(p, false);
82}
83
84#ifdef CONFIG_PROC_FS
85
86enum { MAX_IORES_LEVEL = 5 };
87
88static void *r_start(struct seq_file *m, loff_t *pos)
89 __acquires(resource_lock)
90{
91 struct resource *p = PDE_DATA(file_inode(m->file));
92 loff_t l = 0;
93 read_lock(&resource_lock);
94 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
95 ;
96 return p;
97}
98
99static void r_stop(struct seq_file *m, void *v)
100 __releases(resource_lock)
101{
102 read_unlock(&resource_lock);
103}
104
105static int r_show(struct seq_file *m, void *v)
106{
107 struct resource *root = PDE_DATA(file_inode(m->file));
108 struct resource *r = v, *p;
109 unsigned long long start, end;
110 int width = root->end < 0x10000 ? 4 : 8;
111 int depth;
112
113 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
114 if (p->parent == root)
115 break;
116
117 if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
118 start = r->start;
119 end = r->end;
120 } else {
121 start = end = 0;
122 }
123
124 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
125 depth * 2, "",
126 width, start,
127 width, end,
128 r->name ? r->name : "<BAD>");
129 return 0;
130}
131
132static const struct seq_operations resource_op = {
133 .start = r_start,
134 .next = r_next,
135 .stop = r_stop,
136 .show = r_show,
137};
138
139static int __init ioresources_init(void)
140{
141 proc_create_seq_data("ioports", 0, NULL, &resource_op,
142 &ioport_resource);
143 proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource);
144 return 0;
145}
146__initcall(ioresources_init);
147
148#endif /* CONFIG_PROC_FS */
149
150static void free_resource(struct resource *res)
151{
152 if (!res)
153 return;
154
155 if (!PageSlab(virt_to_head_page(res))) {
156 spin_lock(&bootmem_resource_lock);
157 res->sibling = bootmem_resource_free;
158 bootmem_resource_free = res;
159 spin_unlock(&bootmem_resource_lock);
160 } else {
161 kfree(res);
162 }
163}
164
165static struct resource *alloc_resource(gfp_t flags)
166{
167 struct resource *res = NULL;
168
169 spin_lock(&bootmem_resource_lock);
170 if (bootmem_resource_free) {
171 res = bootmem_resource_free;
172 bootmem_resource_free = res->sibling;
173 }
174 spin_unlock(&bootmem_resource_lock);
175
176 if (res)
177 memset(res, 0, sizeof(struct resource));
178 else
179 res = kzalloc(sizeof(struct resource), flags);
180
181 return res;
182}
183
184/* Return the conflict entry if you can't request it */
185static struct resource * __request_resource(struct resource *root, struct resource *new)
186{
187 resource_size_t start = new->start;
188 resource_size_t end = new->end;
189 struct resource *tmp, **p;
190
191 if (end < start)
192 return root;
193 if (start < root->start)
194 return root;
195 if (end > root->end)
196 return root;
197 p = &root->child;
198 for (;;) {
199 tmp = *p;
200 if (!tmp || tmp->start > end) {
201 new->sibling = tmp;
202 *p = new;
203 new->parent = root;
204 return NULL;
205 }
206 p = &tmp->sibling;
207 if (tmp->end < start)
208 continue;
209 return tmp;
210 }
211}
212
213static int __release_resource(struct resource *old, bool release_child)
214{
215 struct resource *tmp, **p, *chd;
216
217 p = &old->parent->child;
218 for (;;) {
219 tmp = *p;
220 if (!tmp)
221 break;
222 if (tmp == old) {
223 if (release_child || !(tmp->child)) {
224 *p = tmp->sibling;
225 } else {
226 for (chd = tmp->child;; chd = chd->sibling) {
227 chd->parent = tmp->parent;
228 if (!(chd->sibling))
229 break;
230 }
231 *p = tmp->child;
232 chd->sibling = tmp->sibling;
233 }
234 old->parent = NULL;
235 return 0;
236 }
237 p = &tmp->sibling;
238 }
239 return -EINVAL;
240}
241
242static void __release_child_resources(struct resource *r)
243{
244 struct resource *tmp, *p;
245 resource_size_t size;
246
247 p = r->child;
248 r->child = NULL;
249 while (p) {
250 tmp = p;
251 p = p->sibling;
252
253 tmp->parent = NULL;
254 tmp->sibling = NULL;
255 __release_child_resources(tmp);
256
257 printk(KERN_DEBUG "release child resource %pR\n", tmp);
258 /* need to restore size, and keep flags */
259 size = resource_size(tmp);
260 tmp->start = 0;
261 tmp->end = size - 1;
262 }
263}
264
265void release_child_resources(struct resource *r)
266{
267 write_lock(&resource_lock);
268 __release_child_resources(r);
269 write_unlock(&resource_lock);
270}
271
272/**
273 * request_resource_conflict - request and reserve an I/O or memory resource
274 * @root: root resource descriptor
275 * @new: resource descriptor desired by caller
276 *
277 * Returns 0 for success, conflict resource on error.
278 */
279struct resource *request_resource_conflict(struct resource *root, struct resource *new)
280{
281 struct resource *conflict;
282
283 write_lock(&resource_lock);
284 conflict = __request_resource(root, new);
285 write_unlock(&resource_lock);
286 return conflict;
287}
288
289/**
290 * request_resource - request and reserve an I/O or memory resource
291 * @root: root resource descriptor
292 * @new: resource descriptor desired by caller
293 *
294 * Returns 0 for success, negative error code on error.
295 */
296int request_resource(struct resource *root, struct resource *new)
297{
298 struct resource *conflict;
299
300 conflict = request_resource_conflict(root, new);
301 return conflict ? -EBUSY : 0;
302}
303
304EXPORT_SYMBOL(request_resource);
305
306/**
307 * release_resource - release a previously reserved resource
308 * @old: resource pointer
309 */
310int release_resource(struct resource *old)
311{
312 int retval;
313
314 write_lock(&resource_lock);
315 retval = __release_resource(old, true);
316 write_unlock(&resource_lock);
317 return retval;
318}
319
320EXPORT_SYMBOL(release_resource);
321
322/**
323 * Finds the lowest iomem resource that covers part of [@start..@end]. The
324 * caller must specify @start, @end, @flags, and @desc (which may be
325 * IORES_DESC_NONE).
326 *
327 * If a resource is found, returns 0 and @*res is overwritten with the part
328 * of the resource that's within [@start..@end]; if none is found, returns
329 * -ENODEV. Returns -EINVAL for invalid parameters.
330 *
331 * This function walks the whole tree and not just first level children
332 * unless @first_lvl is true.
333 *
334 * @start: start address of the resource searched for
335 * @end: end address of same resource
336 * @flags: flags which the resource must have
337 * @desc: descriptor the resource must have
338 * @first_lvl: walk only the first level children, if set
339 * @res: return ptr, if resource found
340 */
341static int find_next_iomem_res(resource_size_t start, resource_size_t end,
342 unsigned long flags, unsigned long desc,
343 bool first_lvl, struct resource *res)
344{
345 bool siblings_only = true;
346 struct resource *p;
347
348 if (!res)
349 return -EINVAL;
350
351 if (start >= end)
352 return -EINVAL;
353
354 read_lock(&resource_lock);
355
356 for (p = iomem_resource.child; p; p = next_resource(p, siblings_only)) {
357 /* If we passed the resource we are looking for, stop */
358 if (p->start > end) {
359 p = NULL;
360 break;
361 }
362
363 /* Skip until we find a range that matches what we look for */
364 if (p->end < start)
365 continue;
366
367 /*
368 * Now that we found a range that matches what we look for,
369 * check the flags and the descriptor. If we were not asked to
370 * use only the first level, start looking at children as well.
371 */
372 siblings_only = first_lvl;
373
374 if ((p->flags & flags) != flags)
375 continue;
376 if ((desc != IORES_DESC_NONE) && (desc != p->desc))
377 continue;
378
379 /* Found a match, break */
380 break;
381 }
382
383 if (p) {
384 /* copy data */
385 res->start = max(start, p->start);
386 res->end = min(end, p->end);
387 res->flags = p->flags;
388 res->desc = p->desc;
389 }
390
391 read_unlock(&resource_lock);
392 return p ? 0 : -ENODEV;
393}
394
395static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
396 unsigned long flags, unsigned long desc,
397 bool first_lvl, void *arg,
398 int (*func)(struct resource *, void *))
399{
400 struct resource res;
401 int ret = -EINVAL;
402
403 while (start < end &&
404 !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) {
405 ret = (*func)(&res, arg);
406 if (ret)
407 break;
408
409 start = res.end + 1;
410 }
411
412 return ret;
413}
414
415/**
416 * Walks through iomem resources and calls func() with matching resource
417 * ranges. This walks through whole tree and not just first level children.
418 * All the memory ranges which overlap start,end and also match flags and
419 * desc are valid candidates.
420 *
421 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
422 * @flags: I/O resource flags
423 * @start: start addr
424 * @end: end addr
425 * @arg: function argument for the callback @func
426 * @func: callback function that is called for each qualifying resource area
427 *
428 * NOTE: For a new descriptor search, define a new IORES_DESC in
429 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
430 */
431int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
432 u64 end, void *arg, int (*func)(struct resource *, void *))
433{
434 return __walk_iomem_res_desc(start, end, flags, desc, false, arg, func);
435}
436EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
437
438/*
439 * This function calls the @func callback against all memory ranges of type
440 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
441 * Now, this function is only for System RAM, it deals with full ranges and
442 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
443 * ranges.
444 */
445int walk_system_ram_res(u64 start, u64 end, void *arg,
446 int (*func)(struct resource *, void *))
447{
448 unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
449
450 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
451 arg, func);
452}
453
454/*
455 * This function calls the @func callback against all memory ranges, which
456 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
457 */
458int walk_mem_res(u64 start, u64 end, void *arg,
459 int (*func)(struct resource *, void *))
460{
461 unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
462
463 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
464 arg, func);
465}
466
467/*
468 * This function calls the @func callback against all memory ranges of type
469 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
470 * It is to be used only for System RAM.
471 *
472 * This will find System RAM ranges that are children of top-level resources
473 * in addition to top-level System RAM resources.
474 */
475int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
476 void *arg, int (*func)(unsigned long, unsigned long, void *))
477{
478 resource_size_t start, end;
479 unsigned long flags;
480 struct resource res;
481 unsigned long pfn, end_pfn;
482 int ret = -EINVAL;
483
484 start = (u64) start_pfn << PAGE_SHIFT;
485 end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
486 flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
487 while (start < end &&
488 !find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
489 false, &res)) {
490 pfn = PFN_UP(res.start);
491 end_pfn = PFN_DOWN(res.end + 1);
492 if (end_pfn > pfn)
493 ret = (*func)(pfn, end_pfn - pfn, arg);
494 if (ret)
495 break;
496 start = res.end + 1;
497 }
498 return ret;
499}
500
501static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
502{
503 return 1;
504}
505
506/*
507 * This generic page_is_ram() returns true if specified address is
508 * registered as System RAM in iomem_resource list.
509 */
510int __weak page_is_ram(unsigned long pfn)
511{
512 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
513}
514EXPORT_SYMBOL_GPL(page_is_ram);
515
516/**
517 * region_intersects() - determine intersection of region with known resources
518 * @start: region start address
519 * @size: size of region
520 * @flags: flags of resource (in iomem_resource)
521 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
522 *
523 * Check if the specified region partially overlaps or fully eclipses a
524 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
525 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
526 * return REGION_MIXED if the region overlaps @flags/@desc and another
527 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
528 * and no other defined resource. Note that REGION_INTERSECTS is also
529 * returned in the case when the specified region overlaps RAM and undefined
530 * memory holes.
531 *
532 * region_intersect() is used by memory remapping functions to ensure
533 * the user is not remapping RAM and is a vast speed up over walking
534 * through the resource table page by page.
535 */
536int region_intersects(resource_size_t start, size_t size, unsigned long flags,
537 unsigned long desc)
538{
539 struct resource res;
540 int type = 0; int other = 0;
541 struct resource *p;
542
543 res.start = start;
544 res.end = start + size - 1;
545
546 read_lock(&resource_lock);
547 for (p = iomem_resource.child; p ; p = p->sibling) {
548 bool is_type = (((p->flags & flags) == flags) &&
549 ((desc == IORES_DESC_NONE) ||
550 (desc == p->desc)));
551
552 if (resource_overlaps(p, &res))
553 is_type ? type++ : other++;
554 }
555 read_unlock(&resource_lock);
556
557 if (other == 0)
558 return type ? REGION_INTERSECTS : REGION_DISJOINT;
559
560 if (type)
561 return REGION_MIXED;
562
563 return REGION_DISJOINT;
564}
565EXPORT_SYMBOL_GPL(region_intersects);
566
567void __weak arch_remove_reservations(struct resource *avail)
568{
569}
570
571static resource_size_t simple_align_resource(void *data,
572 const struct resource *avail,
573 resource_size_t size,
574 resource_size_t align)
575{
576 return avail->start;
577}
578
579static void resource_clip(struct resource *res, resource_size_t min,
580 resource_size_t max)
581{
582 if (res->start < min)
583 res->start = min;
584 if (res->end > max)
585 res->end = max;
586}
587
588/*
589 * Find empty slot in the resource tree with the given range and
590 * alignment constraints
591 */
592static int __find_resource(struct resource *root, struct resource *old,
593 struct resource *new,
594 resource_size_t size,
595 struct resource_constraint *constraint)
596{
597 struct resource *this = root->child;
598 struct resource tmp = *new, avail, alloc;
599
600 tmp.start = root->start;
601 /*
602 * Skip past an allocated resource that starts at 0, since the assignment
603 * of this->start - 1 to tmp->end below would cause an underflow.
604 */
605 if (this && this->start == root->start) {
606 tmp.start = (this == old) ? old->start : this->end + 1;
607 this = this->sibling;
608 }
609 for(;;) {
610 if (this)
611 tmp.end = (this == old) ? this->end : this->start - 1;
612 else
613 tmp.end = root->end;
614
615 if (tmp.end < tmp.start)
616 goto next;
617
618 resource_clip(&tmp, constraint->min, constraint->max);
619 arch_remove_reservations(&tmp);
620
621 /* Check for overflow after ALIGN() */
622 avail.start = ALIGN(tmp.start, constraint->align);
623 avail.end = tmp.end;
624 avail.flags = new->flags & ~IORESOURCE_UNSET;
625 if (avail.start >= tmp.start) {
626 alloc.flags = avail.flags;
627 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
628 size, constraint->align);
629 alloc.end = alloc.start + size - 1;
630 if (alloc.start <= alloc.end &&
631 resource_contains(&avail, &alloc)) {
632 new->start = alloc.start;
633 new->end = alloc.end;
634 return 0;
635 }
636 }
637
638next: if (!this || this->end == root->end)
639 break;
640
641 if (this != old)
642 tmp.start = this->end + 1;
643 this = this->sibling;
644 }
645 return -EBUSY;
646}
647
648/*
649 * Find empty slot in the resource tree given range and alignment.
650 */
651static int find_resource(struct resource *root, struct resource *new,
652 resource_size_t size,
653 struct resource_constraint *constraint)
654{
655 return __find_resource(root, NULL, new, size, constraint);
656}
657
658/**
659 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
660 * The resource will be relocated if the new size cannot be reallocated in the
661 * current location.
662 *
663 * @root: root resource descriptor
664 * @old: resource descriptor desired by caller
665 * @newsize: new size of the resource descriptor
666 * @constraint: the size and alignment constraints to be met.
667 */
668static int reallocate_resource(struct resource *root, struct resource *old,
669 resource_size_t newsize,
670 struct resource_constraint *constraint)
671{
672 int err=0;
673 struct resource new = *old;
674 struct resource *conflict;
675
676 write_lock(&resource_lock);
677
678 if ((err = __find_resource(root, old, &new, newsize, constraint)))
679 goto out;
680
681 if (resource_contains(&new, old)) {
682 old->start = new.start;
683 old->end = new.end;
684 goto out;
685 }
686
687 if (old->child) {
688 err = -EBUSY;
689 goto out;
690 }
691
692 if (resource_contains(old, &new)) {
693 old->start = new.start;
694 old->end = new.end;
695 } else {
696 __release_resource(old, true);
697 *old = new;
698 conflict = __request_resource(root, old);
699 BUG_ON(conflict);
700 }
701out:
702 write_unlock(&resource_lock);
703 return err;
704}
705
706
707/**
708 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
709 * The resource will be reallocated with a new size if it was already allocated
710 * @root: root resource descriptor
711 * @new: resource descriptor desired by caller
712 * @size: requested resource region size
713 * @min: minimum boundary to allocate
714 * @max: maximum boundary to allocate
715 * @align: alignment requested, in bytes
716 * @alignf: alignment function, optional, called if not NULL
717 * @alignf_data: arbitrary data to pass to the @alignf function
718 */
719int allocate_resource(struct resource *root, struct resource *new,
720 resource_size_t size, resource_size_t min,
721 resource_size_t max, resource_size_t align,
722 resource_size_t (*alignf)(void *,
723 const struct resource *,
724 resource_size_t,
725 resource_size_t),
726 void *alignf_data)
727{
728 int err;
729 struct resource_constraint constraint;
730
731 if (!alignf)
732 alignf = simple_align_resource;
733
734 constraint.min = min;
735 constraint.max = max;
736 constraint.align = align;
737 constraint.alignf = alignf;
738 constraint.alignf_data = alignf_data;
739
740 if ( new->parent ) {
741 /* resource is already allocated, try reallocating with
742 the new constraints */
743 return reallocate_resource(root, new, size, &constraint);
744 }
745
746 write_lock(&resource_lock);
747 err = find_resource(root, new, size, &constraint);
748 if (err >= 0 && __request_resource(root, new))
749 err = -EBUSY;
750 write_unlock(&resource_lock);
751 return err;
752}
753
754EXPORT_SYMBOL(allocate_resource);
755
756/**
757 * lookup_resource - find an existing resource by a resource start address
758 * @root: root resource descriptor
759 * @start: resource start address
760 *
761 * Returns a pointer to the resource if found, NULL otherwise
762 */
763struct resource *lookup_resource(struct resource *root, resource_size_t start)
764{
765 struct resource *res;
766
767 read_lock(&resource_lock);
768 for (res = root->child; res; res = res->sibling) {
769 if (res->start == start)
770 break;
771 }
772 read_unlock(&resource_lock);
773
774 return res;
775}
776
777/*
778 * Insert a resource into the resource tree. If successful, return NULL,
779 * otherwise return the conflicting resource (compare to __request_resource())
780 */
781static struct resource * __insert_resource(struct resource *parent, struct resource *new)
782{
783 struct resource *first, *next;
784
785 for (;; parent = first) {
786 first = __request_resource(parent, new);
787 if (!first)
788 return first;
789
790 if (first == parent)
791 return first;
792 if (WARN_ON(first == new)) /* duplicated insertion */
793 return first;
794
795 if ((first->start > new->start) || (first->end < new->end))
796 break;
797 if ((first->start == new->start) && (first->end == new->end))
798 break;
799 }
800
801 for (next = first; ; next = next->sibling) {
802 /* Partial overlap? Bad, and unfixable */
803 if (next->start < new->start || next->end > new->end)
804 return next;
805 if (!next->sibling)
806 break;
807 if (next->sibling->start > new->end)
808 break;
809 }
810
811 new->parent = parent;
812 new->sibling = next->sibling;
813 new->child = first;
814
815 next->sibling = NULL;
816 for (next = first; next; next = next->sibling)
817 next->parent = new;
818
819 if (parent->child == first) {
820 parent->child = new;
821 } else {
822 next = parent->child;
823 while (next->sibling != first)
824 next = next->sibling;
825 next->sibling = new;
826 }
827 return NULL;
828}
829
830/**
831 * insert_resource_conflict - Inserts resource in the resource tree
832 * @parent: parent of the new resource
833 * @new: new resource to insert
834 *
835 * Returns 0 on success, conflict resource if the resource can't be inserted.
836 *
837 * This function is equivalent to request_resource_conflict when no conflict
838 * happens. If a conflict happens, and the conflicting resources
839 * entirely fit within the range of the new resource, then the new
840 * resource is inserted and the conflicting resources become children of
841 * the new resource.
842 *
843 * This function is intended for producers of resources, such as FW modules
844 * and bus drivers.
845 */
846struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
847{
848 struct resource *conflict;
849
850 write_lock(&resource_lock);
851 conflict = __insert_resource(parent, new);
852 write_unlock(&resource_lock);
853 return conflict;
854}
855
856/**
857 * insert_resource - Inserts a resource in the resource tree
858 * @parent: parent of the new resource
859 * @new: new resource to insert
860 *
861 * Returns 0 on success, -EBUSY if the resource can't be inserted.
862 *
863 * This function is intended for producers of resources, such as FW modules
864 * and bus drivers.
865 */
866int insert_resource(struct resource *parent, struct resource *new)
867{
868 struct resource *conflict;
869
870 conflict = insert_resource_conflict(parent, new);
871 return conflict ? -EBUSY : 0;
872}
873EXPORT_SYMBOL_GPL(insert_resource);
874
875/**
876 * insert_resource_expand_to_fit - Insert a resource into the resource tree
877 * @root: root resource descriptor
878 * @new: new resource to insert
879 *
880 * Insert a resource into the resource tree, possibly expanding it in order
881 * to make it encompass any conflicting resources.
882 */
883void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
884{
885 if (new->parent)
886 return;
887
888 write_lock(&resource_lock);
889 for (;;) {
890 struct resource *conflict;
891
892 conflict = __insert_resource(root, new);
893 if (!conflict)
894 break;
895 if (conflict == root)
896 break;
897
898 /* Ok, expand resource to cover the conflict, then try again .. */
899 if (conflict->start < new->start)
900 new->start = conflict->start;
901 if (conflict->end > new->end)
902 new->end = conflict->end;
903
904 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
905 }
906 write_unlock(&resource_lock);
907}
908
909/**
910 * remove_resource - Remove a resource in the resource tree
911 * @old: resource to remove
912 *
913 * Returns 0 on success, -EINVAL if the resource is not valid.
914 *
915 * This function removes a resource previously inserted by insert_resource()
916 * or insert_resource_conflict(), and moves the children (if any) up to
917 * where they were before. insert_resource() and insert_resource_conflict()
918 * insert a new resource, and move any conflicting resources down to the
919 * children of the new resource.
920 *
921 * insert_resource(), insert_resource_conflict() and remove_resource() are
922 * intended for producers of resources, such as FW modules and bus drivers.
923 */
924int remove_resource(struct resource *old)
925{
926 int retval;
927
928 write_lock(&resource_lock);
929 retval = __release_resource(old, false);
930 write_unlock(&resource_lock);
931 return retval;
932}
933EXPORT_SYMBOL_GPL(remove_resource);
934
935static int __adjust_resource(struct resource *res, resource_size_t start,
936 resource_size_t size)
937{
938 struct resource *tmp, *parent = res->parent;
939 resource_size_t end = start + size - 1;
940 int result = -EBUSY;
941
942 if (!parent)
943 goto skip;
944
945 if ((start < parent->start) || (end > parent->end))
946 goto out;
947
948 if (res->sibling && (res->sibling->start <= end))
949 goto out;
950
951 tmp = parent->child;
952 if (tmp != res) {
953 while (tmp->sibling != res)
954 tmp = tmp->sibling;
955 if (start <= tmp->end)
956 goto out;
957 }
958
959skip:
960 for (tmp = res->child; tmp; tmp = tmp->sibling)
961 if ((tmp->start < start) || (tmp->end > end))
962 goto out;
963
964 res->start = start;
965 res->end = end;
966 result = 0;
967
968 out:
969 return result;
970}
971
972/**
973 * adjust_resource - modify a resource's start and size
974 * @res: resource to modify
975 * @start: new start value
976 * @size: new size
977 *
978 * Given an existing resource, change its start and size to match the
979 * arguments. Returns 0 on success, -EBUSY if it can't fit.
980 * Existing children of the resource are assumed to be immutable.
981 */
982int adjust_resource(struct resource *res, resource_size_t start,
983 resource_size_t size)
984{
985 int result;
986
987 write_lock(&resource_lock);
988 result = __adjust_resource(res, start, size);
989 write_unlock(&resource_lock);
990 return result;
991}
992EXPORT_SYMBOL(adjust_resource);
993
994static void __init
995__reserve_region_with_split(struct resource *root, resource_size_t start,
996 resource_size_t end, const char *name)
997{
998 struct resource *parent = root;
999 struct resource *conflict;
1000 struct resource *res = alloc_resource(GFP_ATOMIC);
1001 struct resource *next_res = NULL;
1002 int type = resource_type(root);
1003
1004 if (!res)
1005 return;
1006
1007 res->name = name;
1008 res->start = start;
1009 res->end = end;
1010 res->flags = type | IORESOURCE_BUSY;
1011 res->desc = IORES_DESC_NONE;
1012
1013 while (1) {
1014
1015 conflict = __request_resource(parent, res);
1016 if (!conflict) {
1017 if (!next_res)
1018 break;
1019 res = next_res;
1020 next_res = NULL;
1021 continue;
1022 }
1023
1024 /* conflict covered whole area */
1025 if (conflict->start <= res->start &&
1026 conflict->end >= res->end) {
1027 free_resource(res);
1028 WARN_ON(next_res);
1029 break;
1030 }
1031
1032 /* failed, split and try again */
1033 if (conflict->start > res->start) {
1034 end = res->end;
1035 res->end = conflict->start - 1;
1036 if (conflict->end < end) {
1037 next_res = alloc_resource(GFP_ATOMIC);
1038 if (!next_res) {
1039 free_resource(res);
1040 break;
1041 }
1042 next_res->name = name;
1043 next_res->start = conflict->end + 1;
1044 next_res->end = end;
1045 next_res->flags = type | IORESOURCE_BUSY;
1046 next_res->desc = IORES_DESC_NONE;
1047 }
1048 } else {
1049 res->start = conflict->end + 1;
1050 }
1051 }
1052
1053}
1054
1055void __init
1056reserve_region_with_split(struct resource *root, resource_size_t start,
1057 resource_size_t end, const char *name)
1058{
1059 int abort = 0;
1060
1061 write_lock(&resource_lock);
1062 if (root->start > start || root->end < end) {
1063 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1064 (unsigned long long)start, (unsigned long long)end,
1065 root);
1066 if (start > root->end || end < root->start)
1067 abort = 1;
1068 else {
1069 if (end > root->end)
1070 end = root->end;
1071 if (start < root->start)
1072 start = root->start;
1073 pr_err("fixing request to [0x%llx-0x%llx]\n",
1074 (unsigned long long)start,
1075 (unsigned long long)end);
1076 }
1077 dump_stack();
1078 }
1079 if (!abort)
1080 __reserve_region_with_split(root, start, end, name);
1081 write_unlock(&resource_lock);
1082}
1083
1084/**
1085 * resource_alignment - calculate resource's alignment
1086 * @res: resource pointer
1087 *
1088 * Returns alignment on success, 0 (invalid alignment) on failure.
1089 */
1090resource_size_t resource_alignment(struct resource *res)
1091{
1092 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1093 case IORESOURCE_SIZEALIGN:
1094 return resource_size(res);
1095 case IORESOURCE_STARTALIGN:
1096 return res->start;
1097 default:
1098 return 0;
1099 }
1100}
1101
1102/*
1103 * This is compatibility stuff for IO resources.
1104 *
1105 * Note how this, unlike the above, knows about
1106 * the IO flag meanings (busy etc).
1107 *
1108 * request_region creates a new busy region.
1109 *
1110 * release_region releases a matching busy region.
1111 */
1112
1113static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1114
1115/**
1116 * __request_region - create a new busy resource region
1117 * @parent: parent resource descriptor
1118 * @start: resource start address
1119 * @n: resource region size
1120 * @name: reserving caller's ID string
1121 * @flags: IO resource flags
1122 */
1123struct resource * __request_region(struct resource *parent,
1124 resource_size_t start, resource_size_t n,
1125 const char *name, int flags)
1126{
1127 DECLARE_WAITQUEUE(wait, current);
1128 struct resource *res = alloc_resource(GFP_KERNEL);
1129 struct resource *orig_parent = parent;
1130
1131 if (!res)
1132 return NULL;
1133
1134 res->name = name;
1135 res->start = start;
1136 res->end = start + n - 1;
1137
1138 write_lock(&resource_lock);
1139
1140 for (;;) {
1141 struct resource *conflict;
1142
1143 res->flags = resource_type(parent) | resource_ext_type(parent);
1144 res->flags |= IORESOURCE_BUSY | flags;
1145 res->desc = parent->desc;
1146
1147 conflict = __request_resource(parent, res);
1148 if (!conflict)
1149 break;
1150 /*
1151 * mm/hmm.c reserves physical addresses which then
1152 * become unavailable to other users. Conflicts are
1153 * not expected. Warn to aid debugging if encountered.
1154 */
1155 if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1156 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1157 conflict->name, conflict, res);
1158 }
1159 if (conflict != parent) {
1160 if (!(conflict->flags & IORESOURCE_BUSY)) {
1161 parent = conflict;
1162 continue;
1163 }
1164 }
1165 if (conflict->flags & flags & IORESOURCE_MUXED) {
1166 add_wait_queue(&muxed_resource_wait, &wait);
1167 write_unlock(&resource_lock);
1168 set_current_state(TASK_UNINTERRUPTIBLE);
1169 schedule();
1170 remove_wait_queue(&muxed_resource_wait, &wait);
1171 write_lock(&resource_lock);
1172 continue;
1173 }
1174 /* Uhhuh, that didn't work out.. */
1175 free_resource(res);
1176 res = NULL;
1177 break;
1178 }
1179 write_unlock(&resource_lock);
1180
1181 if (res && orig_parent == &iomem_resource)
1182 revoke_devmem(res);
1183
1184 return res;
1185}
1186EXPORT_SYMBOL(__request_region);
1187
1188/**
1189 * __release_region - release a previously reserved resource region
1190 * @parent: parent resource descriptor
1191 * @start: resource start address
1192 * @n: resource region size
1193 *
1194 * The described resource region must match a currently busy region.
1195 */
1196void __release_region(struct resource *parent, resource_size_t start,
1197 resource_size_t n)
1198{
1199 struct resource **p;
1200 resource_size_t end;
1201
1202 p = &parent->child;
1203 end = start + n - 1;
1204
1205 write_lock(&resource_lock);
1206
1207 for (;;) {
1208 struct resource *res = *p;
1209
1210 if (!res)
1211 break;
1212 if (res->start <= start && res->end >= end) {
1213 if (!(res->flags & IORESOURCE_BUSY)) {
1214 p = &res->child;
1215 continue;
1216 }
1217 if (res->start != start || res->end != end)
1218 break;
1219 *p = res->sibling;
1220 write_unlock(&resource_lock);
1221 if (res->flags & IORESOURCE_MUXED)
1222 wake_up(&muxed_resource_wait);
1223 free_resource(res);
1224 return;
1225 }
1226 p = &res->sibling;
1227 }
1228
1229 write_unlock(&resource_lock);
1230
1231 printk(KERN_WARNING "Trying to free nonexistent resource "
1232 "<%016llx-%016llx>\n", (unsigned long long)start,
1233 (unsigned long long)end);
1234}
1235EXPORT_SYMBOL(__release_region);
1236
1237#ifdef CONFIG_MEMORY_HOTREMOVE
1238/**
1239 * release_mem_region_adjustable - release a previously reserved memory region
1240 * @parent: parent resource descriptor
1241 * @start: resource start address
1242 * @size: resource region size
1243 *
1244 * This interface is intended for memory hot-delete. The requested region
1245 * is released from a currently busy memory resource. The requested region
1246 * must either match exactly or fit into a single busy resource entry. In
1247 * the latter case, the remaining resource is adjusted accordingly.
1248 * Existing children of the busy memory resource must be immutable in the
1249 * request.
1250 *
1251 * Note:
1252 * - Additional release conditions, such as overlapping region, can be
1253 * supported after they are confirmed as valid cases.
1254 * - When a busy memory resource gets split into two entries, the code
1255 * assumes that all children remain in the lower address entry for
1256 * simplicity. Enhance this logic when necessary.
1257 */
1258int release_mem_region_adjustable(struct resource *parent,
1259 resource_size_t start, resource_size_t size)
1260{
1261 struct resource **p;
1262 struct resource *res;
1263 struct resource *new_res;
1264 resource_size_t end;
1265 int ret = -EINVAL;
1266
1267 end = start + size - 1;
1268 if ((start < parent->start) || (end > parent->end))
1269 return ret;
1270
1271 /* The alloc_resource() result gets checked later */
1272 new_res = alloc_resource(GFP_KERNEL);
1273
1274 p = &parent->child;
1275 write_lock(&resource_lock);
1276
1277 while ((res = *p)) {
1278 if (res->start >= end)
1279 break;
1280
1281 /* look for the next resource if it does not fit into */
1282 if (res->start > start || res->end < end) {
1283 p = &res->sibling;
1284 continue;
1285 }
1286
1287 /*
1288 * All memory regions added from memory-hotplug path have the
1289 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1290 * this flag, we know that we are dealing with a resource coming
1291 * from HMM/devm. HMM/devm use another mechanism to add/release
1292 * a resource. This goes via devm_request_mem_region and
1293 * devm_release_mem_region.
1294 * HMM/devm take care to release their resources when they want,
1295 * so if we are dealing with them, let us just back off here.
1296 */
1297 if (!(res->flags & IORESOURCE_SYSRAM)) {
1298 ret = 0;
1299 break;
1300 }
1301
1302 if (!(res->flags & IORESOURCE_MEM))
1303 break;
1304
1305 if (!(res->flags & IORESOURCE_BUSY)) {
1306 p = &res->child;
1307 continue;
1308 }
1309
1310 /* found the target resource; let's adjust accordingly */
1311 if (res->start == start && res->end == end) {
1312 /* free the whole entry */
1313 *p = res->sibling;
1314 free_resource(res);
1315 ret = 0;
1316 } else if (res->start == start && res->end != end) {
1317 /* adjust the start */
1318 ret = __adjust_resource(res, end + 1,
1319 res->end - end);
1320 } else if (res->start != start && res->end == end) {
1321 /* adjust the end */
1322 ret = __adjust_resource(res, res->start,
1323 start - res->start);
1324 } else {
1325 /* split into two entries */
1326 if (!new_res) {
1327 ret = -ENOMEM;
1328 break;
1329 }
1330 new_res->name = res->name;
1331 new_res->start = end + 1;
1332 new_res->end = res->end;
1333 new_res->flags = res->flags;
1334 new_res->desc = res->desc;
1335 new_res->parent = res->parent;
1336 new_res->sibling = res->sibling;
1337 new_res->child = NULL;
1338
1339 ret = __adjust_resource(res, res->start,
1340 start - res->start);
1341 if (ret)
1342 break;
1343 res->sibling = new_res;
1344 new_res = NULL;
1345 }
1346
1347 break;
1348 }
1349
1350 write_unlock(&resource_lock);
1351 free_resource(new_res);
1352 return ret;
1353}
1354#endif /* CONFIG_MEMORY_HOTREMOVE */
1355
1356/*
1357 * Managed region resource
1358 */
1359static void devm_resource_release(struct device *dev, void *ptr)
1360{
1361 struct resource **r = ptr;
1362
1363 release_resource(*r);
1364}
1365
1366/**
1367 * devm_request_resource() - request and reserve an I/O or memory resource
1368 * @dev: device for which to request the resource
1369 * @root: root of the resource tree from which to request the resource
1370 * @new: descriptor of the resource to request
1371 *
1372 * This is a device-managed version of request_resource(). There is usually
1373 * no need to release resources requested by this function explicitly since
1374 * that will be taken care of when the device is unbound from its driver.
1375 * If for some reason the resource needs to be released explicitly, because
1376 * of ordering issues for example, drivers must call devm_release_resource()
1377 * rather than the regular release_resource().
1378 *
1379 * When a conflict is detected between any existing resources and the newly
1380 * requested resource, an error message will be printed.
1381 *
1382 * Returns 0 on success or a negative error code on failure.
1383 */
1384int devm_request_resource(struct device *dev, struct resource *root,
1385 struct resource *new)
1386{
1387 struct resource *conflict, **ptr;
1388
1389 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1390 if (!ptr)
1391 return -ENOMEM;
1392
1393 *ptr = new;
1394
1395 conflict = request_resource_conflict(root, new);
1396 if (conflict) {
1397 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1398 new, conflict->name, conflict);
1399 devres_free(ptr);
1400 return -EBUSY;
1401 }
1402
1403 devres_add(dev, ptr);
1404 return 0;
1405}
1406EXPORT_SYMBOL(devm_request_resource);
1407
1408static int devm_resource_match(struct device *dev, void *res, void *data)
1409{
1410 struct resource **ptr = res;
1411
1412 return *ptr == data;
1413}
1414
1415/**
1416 * devm_release_resource() - release a previously requested resource
1417 * @dev: device for which to release the resource
1418 * @new: descriptor of the resource to release
1419 *
1420 * Releases a resource previously requested using devm_request_resource().
1421 */
1422void devm_release_resource(struct device *dev, struct resource *new)
1423{
1424 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1425 new));
1426}
1427EXPORT_SYMBOL(devm_release_resource);
1428
1429struct region_devres {
1430 struct resource *parent;
1431 resource_size_t start;
1432 resource_size_t n;
1433};
1434
1435static void devm_region_release(struct device *dev, void *res)
1436{
1437 struct region_devres *this = res;
1438
1439 __release_region(this->parent, this->start, this->n);
1440}
1441
1442static int devm_region_match(struct device *dev, void *res, void *match_data)
1443{
1444 struct region_devres *this = res, *match = match_data;
1445
1446 return this->parent == match->parent &&
1447 this->start == match->start && this->n == match->n;
1448}
1449
1450struct resource *
1451__devm_request_region(struct device *dev, struct resource *parent,
1452 resource_size_t start, resource_size_t n, const char *name)
1453{
1454 struct region_devres *dr = NULL;
1455 struct resource *res;
1456
1457 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1458 GFP_KERNEL);
1459 if (!dr)
1460 return NULL;
1461
1462 dr->parent = parent;
1463 dr->start = start;
1464 dr->n = n;
1465
1466 res = __request_region(parent, start, n, name, 0);
1467 if (res)
1468 devres_add(dev, dr);
1469 else
1470 devres_free(dr);
1471
1472 return res;
1473}
1474EXPORT_SYMBOL(__devm_request_region);
1475
1476void __devm_release_region(struct device *dev, struct resource *parent,
1477 resource_size_t start, resource_size_t n)
1478{
1479 struct region_devres match_data = { parent, start, n };
1480
1481 __release_region(parent, start, n);
1482 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1483 &match_data));
1484}
1485EXPORT_SYMBOL(__devm_release_region);
1486
1487/*
1488 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1489 */
1490#define MAXRESERVE 4
1491static int __init reserve_setup(char *str)
1492{
1493 static int reserved;
1494 static struct resource reserve[MAXRESERVE];
1495
1496 for (;;) {
1497 unsigned int io_start, io_num;
1498 int x = reserved;
1499 struct resource *parent;
1500
1501 if (get_option(&str, &io_start) != 2)
1502 break;
1503 if (get_option(&str, &io_num) == 0)
1504 break;
1505 if (x < MAXRESERVE) {
1506 struct resource *res = reserve + x;
1507
1508 /*
1509 * If the region starts below 0x10000, we assume it's
1510 * I/O port space; otherwise assume it's memory.
1511 */
1512 if (io_start < 0x10000) {
1513 res->flags = IORESOURCE_IO;
1514 parent = &ioport_resource;
1515 } else {
1516 res->flags = IORESOURCE_MEM;
1517 parent = &iomem_resource;
1518 }
1519 res->name = "reserved";
1520 res->start = io_start;
1521 res->end = io_start + io_num - 1;
1522 res->flags |= IORESOURCE_BUSY;
1523 res->desc = IORES_DESC_NONE;
1524 res->child = NULL;
1525 if (request_resource(parent, res) == 0)
1526 reserved = x+1;
1527 }
1528 }
1529 return 1;
1530}
1531__setup("reserve=", reserve_setup);
1532
1533/*
1534 * Check if the requested addr and size spans more than any slot in the
1535 * iomem resource tree.
1536 */
1537int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1538{
1539 struct resource *p = &iomem_resource;
1540 int err = 0;
1541 loff_t l;
1542
1543 read_lock(&resource_lock);
1544 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1545 /*
1546 * We can probably skip the resources without
1547 * IORESOURCE_IO attribute?
1548 */
1549 if (p->start >= addr + size)
1550 continue;
1551 if (p->end < addr)
1552 continue;
1553 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1554 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1555 continue;
1556 /*
1557 * if a resource is "BUSY", it's not a hardware resource
1558 * but a driver mapping of such a resource; we don't want
1559 * to warn for those; some drivers legitimately map only
1560 * partial hardware resources. (example: vesafb)
1561 */
1562 if (p->flags & IORESOURCE_BUSY)
1563 continue;
1564
1565 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1566 (unsigned long long)addr,
1567 (unsigned long long)(addr + size - 1),
1568 p->name, p);
1569 err = -1;
1570 break;
1571 }
1572 read_unlock(&resource_lock);
1573
1574 return err;
1575}
1576
1577#ifdef CONFIG_STRICT_DEVMEM
1578static int strict_iomem_checks = 1;
1579#else
1580static int strict_iomem_checks;
1581#endif
1582
1583/*
1584 * check if an address is reserved in the iomem resource tree
1585 * returns true if reserved, false if not reserved.
1586 */
1587bool iomem_is_exclusive(u64 addr)
1588{
1589 struct resource *p = &iomem_resource;
1590 bool err = false;
1591 loff_t l;
1592 int size = PAGE_SIZE;
1593
1594 if (!strict_iomem_checks)
1595 return false;
1596
1597 addr = addr & PAGE_MASK;
1598
1599 read_lock(&resource_lock);
1600 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1601 /*
1602 * We can probably skip the resources without
1603 * IORESOURCE_IO attribute?
1604 */
1605 if (p->start >= addr + size)
1606 break;
1607 if (p->end < addr)
1608 continue;
1609 /*
1610 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1611 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1612 * resource is busy.
1613 */
1614 if ((p->flags & IORESOURCE_BUSY) == 0)
1615 continue;
1616 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1617 || p->flags & IORESOURCE_EXCLUSIVE) {
1618 err = true;
1619 break;
1620 }
1621 }
1622 read_unlock(&resource_lock);
1623
1624 return err;
1625}
1626
1627struct resource_entry *resource_list_create_entry(struct resource *res,
1628 size_t extra_size)
1629{
1630 struct resource_entry *entry;
1631
1632 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1633 if (entry) {
1634 INIT_LIST_HEAD(&entry->node);
1635 entry->res = res ? res : &entry->__res;
1636 }
1637
1638 return entry;
1639}
1640EXPORT_SYMBOL(resource_list_create_entry);
1641
1642void resource_list_free(struct list_head *head)
1643{
1644 struct resource_entry *entry, *tmp;
1645
1646 list_for_each_entry_safe(entry, tmp, head, node)
1647 resource_list_destroy_entry(entry);
1648}
1649EXPORT_SYMBOL(resource_list_free);
1650
1651#ifdef CONFIG_DEVICE_PRIVATE
1652static struct resource *__request_free_mem_region(struct device *dev,
1653 struct resource *base, unsigned long size, const char *name)
1654{
1655 resource_size_t end, addr;
1656 struct resource *res;
1657
1658 size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
1659 end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
1660 addr = end - size + 1UL;
1661
1662 for (; addr > size && addr >= base->start; addr -= size) {
1663 if (region_intersects(addr, size, 0, IORES_DESC_NONE) !=
1664 REGION_DISJOINT)
1665 continue;
1666
1667 if (dev)
1668 res = devm_request_mem_region(dev, addr, size, name);
1669 else
1670 res = request_mem_region(addr, size, name);
1671 if (!res)
1672 return ERR_PTR(-ENOMEM);
1673 res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
1674 return res;
1675 }
1676
1677 return ERR_PTR(-ERANGE);
1678}
1679
1680/**
1681 * devm_request_free_mem_region - find free region for device private memory
1682 *
1683 * @dev: device struct to bind the resource to
1684 * @size: size in bytes of the device memory to add
1685 * @base: resource tree to look in
1686 *
1687 * This function tries to find an empty range of physical address big enough to
1688 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1689 * memory, which in turn allocates struct pages.
1690 */
1691struct resource *devm_request_free_mem_region(struct device *dev,
1692 struct resource *base, unsigned long size)
1693{
1694 return __request_free_mem_region(dev, base, size, dev_name(dev));
1695}
1696EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
1697
1698struct resource *request_free_mem_region(struct resource *base,
1699 unsigned long size, const char *name)
1700{
1701 return __request_free_mem_region(NULL, base, size, name);
1702}
1703EXPORT_SYMBOL_GPL(request_free_mem_region);
1704
1705#endif /* CONFIG_DEVICE_PRIVATE */
1706
1707static int __init strict_iomem(char *str)
1708{
1709 if (strstr(str, "relaxed"))
1710 strict_iomem_checks = 0;
1711 if (strstr(str, "strict"))
1712 strict_iomem_checks = 1;
1713 return 1;
1714}
1715
1716__setup("iomem=", strict_iomem);