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