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TOMOYO Linux Cross Reference
Linux/kernel/resource.c

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

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