Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/kernel/resource.c

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