projects/linux·blob v3.6 · refs

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1/*
2 * linux/kernel/resource.c
3 *
4 * Copyright (C) 1999 Linus Torvalds
5 * Copyright (C) 1999 Martin Mares <[email protected]>
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 <asm/io.h>
25
26
27struct resource ioport_resource = {
28 .name = "PCI IO",
29 .start = 0,
30 .end = IO_SPACE_LIMIT,
31 .flags = IORESOURCE_IO,
32};
33EXPORT_SYMBOL(ioport_resource);
34
35struct resource iomem_resource = {
36 .name = "PCI mem",
37 .start = 0,
38 .end = -1,
39 .flags = IORESOURCE_MEM,
40};
41EXPORT_SYMBOL(iomem_resource);
42
43/* constraints to be met while allocating resources */
44struct resource_constraint {
45 resource_size_t min, max, align;
46 resource_size_t (*alignf)(void *, const struct resource *,
47 resource_size_t, resource_size_t);
48 void *alignf_data;
49};
50
51static DEFINE_RWLOCK(resource_lock);
52
53static void *r_next(struct seq_file *m, void *v, loff_t *pos)
54{
55 struct resource *p = v;
56 (*pos)++;
57 if (p->child)
58 return p->child;
59 while (!p->sibling && p->parent)
60 p = p->parent;
61 return p->sibling;
62}
63
64#ifdef CONFIG_PROC_FS
65
66enum { MAX_IORES_LEVEL = 5 };
67
68static void *r_start(struct seq_file *m, loff_t *pos)
69 __acquires(resource_lock)
70{
71 struct resource *p = m->private;
72 loff_t l = 0;
73 read_lock(&resource_lock);
74 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
75 ;
76 return p;
77}
78
79static void r_stop(struct seq_file *m, void *v)
80 __releases(resource_lock)
81{
82 read_unlock(&resource_lock);
83}
84
85static int r_show(struct seq_file *m, void *v)
86{
87 struct resource *root = m->private;
88 struct resource *r = v, *p;
89 int width = root->end < 0x10000 ? 4 : 8;
90 int depth;
91
92 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
93 if (p->parent == root)
94 break;
95 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
96 depth * 2, "",
97 width, (unsigned long long) r->start,
98 width, (unsigned long long) r->end,
99 r->name ? r->name : "<BAD>");
100 return 0;
101}
102
103static const struct seq_operations resource_op = {
104 .start = r_start,
105 .next = r_next,
106 .stop = r_stop,
107 .show = r_show,
108};
109
110static int ioports_open(struct inode *inode, struct file *file)
111{
112 int res = seq_open(file, &resource_op);
113 if (!res) {
114 struct seq_file *m = file->private_data;
115 m->private = &ioport_resource;
116 }
117 return res;
118}
119
120static int iomem_open(struct inode *inode, struct file *file)
121{
122 int res = seq_open(file, &resource_op);
123 if (!res) {
124 struct seq_file *m = file->private_data;
125 m->private = &iomem_resource;
126 }
127 return res;
128}
129
130static const struct file_operations proc_ioports_operations = {
131 .open = ioports_open,
132 .read = seq_read,
133 .llseek = seq_lseek,
134 .release = seq_release,
135};
136
137static const struct file_operations proc_iomem_operations = {
138 .open = iomem_open,
139 .read = seq_read,
140 .llseek = seq_lseek,
141 .release = seq_release,
142};
143
144static int __init ioresources_init(void)
145{
146 proc_create("ioports", 0, NULL, &proc_ioports_operations);
147 proc_create("iomem", 0, NULL, &proc_iomem_operations);
148 return 0;
149}
150__initcall(ioresources_init);
151
152#endif /* CONFIG_PROC_FS */
153
154/* Return the conflict entry if you can't request it */
155static struct resource * __request_resource(struct resource *root, struct resource *new)
156{
157 resource_size_t start = new->start;
158 resource_size_t end = new->end;
159 struct resource *tmp, **p;
160
161 if (end < start)
162 return root;
163 if (start < root->start)
164 return root;
165 if (end > root->end)
166 return root;
167 p = &root->child;
168 for (;;) {
169 tmp = *p;
170 if (!tmp || tmp->start > end) {
171 new->sibling = tmp;
172 *p = new;
173 new->parent = root;
174 return NULL;
175 }
176 p = &tmp->sibling;
177 if (tmp->end < start)
178 continue;
179 return tmp;
180 }
181}
182
183static int __release_resource(struct resource *old)
184{
185 struct resource *tmp, **p;
186
187 p = &old->parent->child;
188 for (;;) {
189 tmp = *p;
190 if (!tmp)
191 break;
192 if (tmp == old) {
193 *p = tmp->sibling;
194 old->parent = NULL;
195 return 0;
196 }
197 p = &tmp->sibling;
198 }
199 return -EINVAL;
200}
201
202static void __release_child_resources(struct resource *r)
203{
204 struct resource *tmp, *p;
205 resource_size_t size;
206
207 p = r->child;
208 r->child = NULL;
209 while (p) {
210 tmp = p;
211 p = p->sibling;
212
213 tmp->parent = NULL;
214 tmp->sibling = NULL;
215 __release_child_resources(tmp);
216
217 printk(KERN_DEBUG "release child resource %pR\n", tmp);
218 /* need to restore size, and keep flags */
219 size = resource_size(tmp);
220 tmp->start = 0;
221 tmp->end = size - 1;
222 }
223}
224
225void release_child_resources(struct resource *r)
226{
227 write_lock(&resource_lock);
228 __release_child_resources(r);
229 write_unlock(&resource_lock);
230}
231
232/**
233 * request_resource_conflict - request and reserve an I/O or memory resource
234 * @root: root resource descriptor
235 * @new: resource descriptor desired by caller
236 *
237 * Returns 0 for success, conflict resource on error.
238 */
239struct resource *request_resource_conflict(struct resource *root, struct resource *new)
240{
241 struct resource *conflict;
242
243 write_lock(&resource_lock);
244 conflict = __request_resource(root, new);
245 write_unlock(&resource_lock);
246 return conflict;
247}
248
249/**
250 * request_resource - request and reserve an I/O or memory resource
251 * @root: root resource descriptor
252 * @new: resource descriptor desired by caller
253 *
254 * Returns 0 for success, negative error code on error.
255 */
256int request_resource(struct resource *root, struct resource *new)
257{
258 struct resource *conflict;
259
260 conflict = request_resource_conflict(root, new);
261 return conflict ? -EBUSY : 0;
262}
263
264EXPORT_SYMBOL(request_resource);
265
266/**
267 * release_resource - release a previously reserved resource
268 * @old: resource pointer
269 */
270int release_resource(struct resource *old)
271{
272 int retval;
273
274 write_lock(&resource_lock);
275 retval = __release_resource(old);
276 write_unlock(&resource_lock);
277 return retval;
278}
279
280EXPORT_SYMBOL(release_resource);
281
282#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
283/*
284 * Finds the lowest memory reosurce exists within [res->start.res->end)
285 * the caller must specify res->start, res->end, res->flags and "name".
286 * If found, returns 0, res is overwritten, if not found, returns -1.
287 */
288static int find_next_system_ram(struct resource *res, char *name)
289{
290 resource_size_t start, end;
291 struct resource *p;
292
293 BUG_ON(!res);
294
295 start = res->start;
296 end = res->end;
297 BUG_ON(start >= end);
298
299 read_lock(&resource_lock);
300 for (p = iomem_resource.child; p ; p = p->sibling) {
301 /* system ram is just marked as IORESOURCE_MEM */
302 if (p->flags != res->flags)
303 continue;
304 if (name && strcmp(p->name, name))
305 continue;
306 if (p->start > end) {
307 p = NULL;
308 break;
309 }
310 if ((p->end >= start) && (p->start < end))
311 break;
312 }
313 read_unlock(&resource_lock);
314 if (!p)
315 return -1;
316 /* copy data */
317 if (res->start < p->start)
318 res->start = p->start;
319 if (res->end > p->end)
320 res->end = p->end;
321 return 0;
322}
323
324/*
325 * This function calls callback against all memory range of "System RAM"
326 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
327 * Now, this function is only for "System RAM".
328 */
329int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
330 void *arg, int (*func)(unsigned long, unsigned long, void *))
331{
332 struct resource res;
333 unsigned long pfn, end_pfn;
334 u64 orig_end;
335 int ret = -1;
336
337 res.start = (u64) start_pfn << PAGE_SHIFT;
338 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
339 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
340 orig_end = res.end;
341 while ((res.start < res.end) &&
342 (find_next_system_ram(&res, "System RAM") >= 0)) {
343 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
344 end_pfn = (res.end + 1) >> PAGE_SHIFT;
345 if (end_pfn > pfn)
346 ret = (*func)(pfn, end_pfn - pfn, arg);
347 if (ret)
348 break;
349 res.start = res.end + 1;
350 res.end = orig_end;
351 }
352 return ret;
353}
354
355#endif
356
357static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
358{
359 return 1;
360}
361/*
362 * This generic page_is_ram() returns true if specified address is
363 * registered as "System RAM" in iomem_resource list.
364 */
365int __weak page_is_ram(unsigned long pfn)
366{
367 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
368}
369
370void __weak arch_remove_reservations(struct resource *avail)
371{
372}
373
374static resource_size_t simple_align_resource(void *data,
375 const struct resource *avail,
376 resource_size_t size,
377 resource_size_t align)
378{
379 return avail->start;
380}
381
382static void resource_clip(struct resource *res, resource_size_t min,
383 resource_size_t max)
384{
385 if (res->start < min)
386 res->start = min;
387 if (res->end > max)
388 res->end = max;
389}
390
391static bool resource_contains(struct resource *res1, struct resource *res2)
392{
393 return res1->start <= res2->start && res1->end >= res2->end;
394}
395
396/*
397 * Find empty slot in the resource tree with the given range and
398 * alignment constraints
399 */
400static int __find_resource(struct resource *root, struct resource *old,
401 struct resource *new,
402 resource_size_t size,
403 struct resource_constraint *constraint)
404{
405 struct resource *this = root->child;
406 struct resource tmp = *new, avail, alloc;
407
408 tmp.flags = new->flags;
409 tmp.start = root->start;
410 /*
411 * Skip past an allocated resource that starts at 0, since the assignment
412 * of this->start - 1 to tmp->end below would cause an underflow.
413 */
414 if (this && this->start == root->start) {
415 tmp.start = (this == old) ? old->start : this->end + 1;
416 this = this->sibling;
417 }
418 for(;;) {
419 if (this)
420 tmp.end = (this == old) ? this->end : this->start - 1;
421 else
422 tmp.end = root->end;
423
424 if (tmp.end < tmp.start)
425 goto next;
426
427 resource_clip(&tmp, constraint->min, constraint->max);
428 arch_remove_reservations(&tmp);
429
430 /* Check for overflow after ALIGN() */
431 avail = *new;
432 avail.start = ALIGN(tmp.start, constraint->align);
433 avail.end = tmp.end;
434 if (avail.start >= tmp.start) {
435 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
436 size, constraint->align);
437 alloc.end = alloc.start + size - 1;
438 if (resource_contains(&avail, &alloc)) {
439 new->start = alloc.start;
440 new->end = alloc.end;
441 return 0;
442 }
443 }
444
445next: if (!this || this->end == root->end)
446 break;
447
448 if (this != old)
449 tmp.start = this->end + 1;
450 this = this->sibling;
451 }
452 return -EBUSY;
453}
454
455/*
456 * Find empty slot in the resource tree given range and alignment.
457 */
458static int find_resource(struct resource *root, struct resource *new,
459 resource_size_t size,
460 struct resource_constraint *constraint)
461{
462 return __find_resource(root, NULL, new, size, constraint);
463}
464
465/**
466 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
467 * The resource will be relocated if the new size cannot be reallocated in the
468 * current location.
469 *
470 * @root: root resource descriptor
471 * @old: resource descriptor desired by caller
472 * @newsize: new size of the resource descriptor
473 * @constraint: the size and alignment constraints to be met.
474 */
475int reallocate_resource(struct resource *root, struct resource *old,
476 resource_size_t newsize,
477 struct resource_constraint *constraint)
478{
479 int err=0;
480 struct resource new = *old;
481 struct resource *conflict;
482
483 write_lock(&resource_lock);
484
485 if ((err = __find_resource(root, old, &new, newsize, constraint)))
486 goto out;
487
488 if (resource_contains(&new, old)) {
489 old->start = new.start;
490 old->end = new.end;
491 goto out;
492 }
493
494 if (old->child) {
495 err = -EBUSY;
496 goto out;
497 }
498
499 if (resource_contains(old, &new)) {
500 old->start = new.start;
501 old->end = new.end;
502 } else {
503 __release_resource(old);
504 *old = new;
505 conflict = __request_resource(root, old);
506 BUG_ON(conflict);
507 }
508out:
509 write_unlock(&resource_lock);
510 return err;
511}
512
513
514/**
515 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
516 * The resource will be reallocated with a new size if it was already allocated
517 * @root: root resource descriptor
518 * @new: resource descriptor desired by caller
519 * @size: requested resource region size
520 * @min: minimum boundary to allocate
521 * @max: maximum boundary to allocate
522 * @align: alignment requested, in bytes
523 * @alignf: alignment function, optional, called if not NULL
524 * @alignf_data: arbitrary data to pass to the @alignf function
525 */
526int allocate_resource(struct resource *root, struct resource *new,
527 resource_size_t size, resource_size_t min,
528 resource_size_t max, resource_size_t align,
529 resource_size_t (*alignf)(void *,
530 const struct resource *,
531 resource_size_t,
532 resource_size_t),
533 void *alignf_data)
534{
535 int err;
536 struct resource_constraint constraint;
537
538 if (!alignf)
539 alignf = simple_align_resource;
540
541 constraint.min = min;
542 constraint.max = max;
543 constraint.align = align;
544 constraint.alignf = alignf;
545 constraint.alignf_data = alignf_data;
546
547 if ( new->parent ) {
548 /* resource is already allocated, try reallocating with
549 the new constraints */
550 return reallocate_resource(root, new, size, &constraint);
551 }
552
553 write_lock(&resource_lock);
554 err = find_resource(root, new, size, &constraint);
555 if (err >= 0 && __request_resource(root, new))
556 err = -EBUSY;
557 write_unlock(&resource_lock);
558 return err;
559}
560
561EXPORT_SYMBOL(allocate_resource);
562
563/**
564 * lookup_resource - find an existing resource by a resource start address
565 * @root: root resource descriptor
566 * @start: resource start address
567 *
568 * Returns a pointer to the resource if found, NULL otherwise
569 */
570struct resource *lookup_resource(struct resource *root, resource_size_t start)
571{
572 struct resource *res;
573
574 read_lock(&resource_lock);
575 for (res = root->child; res; res = res->sibling) {
576 if (res->start == start)
577 break;
578 }
579 read_unlock(&resource_lock);
580
581 return res;
582}
583
584/*
585 * Insert a resource into the resource tree. If successful, return NULL,
586 * otherwise return the conflicting resource (compare to __request_resource())
587 */
588static struct resource * __insert_resource(struct resource *parent, struct resource *new)
589{
590 struct resource *first, *next;
591
592 for (;; parent = first) {
593 first = __request_resource(parent, new);
594 if (!first)
595 return first;
596
597 if (first == parent)
598 return first;
599 if (WARN_ON(first == new)) /* duplicated insertion */
600 return first;
601
602 if ((first->start > new->start) || (first->end < new->end))
603 break;
604 if ((first->start == new->start) && (first->end == new->end))
605 break;
606 }
607
608 for (next = first; ; next = next->sibling) {
609 /* Partial overlap? Bad, and unfixable */
610 if (next->start < new->start || next->end > new->end)
611 return next;
612 if (!next->sibling)
613 break;
614 if (next->sibling->start > new->end)
615 break;
616 }
617
618 new->parent = parent;
619 new->sibling = next->sibling;
620 new->child = first;
621
622 next->sibling = NULL;
623 for (next = first; next; next = next->sibling)
624 next->parent = new;
625
626 if (parent->child == first) {
627 parent->child = new;
628 } else {
629 next = parent->child;
630 while (next->sibling != first)
631 next = next->sibling;
632 next->sibling = new;
633 }
634 return NULL;
635}
636
637/**
638 * insert_resource_conflict - Inserts resource in the resource tree
639 * @parent: parent of the new resource
640 * @new: new resource to insert
641 *
642 * Returns 0 on success, conflict resource if the resource can't be inserted.
643 *
644 * This function is equivalent to request_resource_conflict when no conflict
645 * happens. If a conflict happens, and the conflicting resources
646 * entirely fit within the range of the new resource, then the new
647 * resource is inserted and the conflicting resources become children of
648 * the new resource.
649 */
650struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
651{
652 struct resource *conflict;
653
654 write_lock(&resource_lock);
655 conflict = __insert_resource(parent, new);
656 write_unlock(&resource_lock);
657 return conflict;
658}
659
660/**
661 * insert_resource - Inserts a resource in the resource tree
662 * @parent: parent of the new resource
663 * @new: new resource to insert
664 *
665 * Returns 0 on success, -EBUSY if the resource can't be inserted.
666 */
667int insert_resource(struct resource *parent, struct resource *new)
668{
669 struct resource *conflict;
670
671 conflict = insert_resource_conflict(parent, new);
672 return conflict ? -EBUSY : 0;
673}
674
675/**
676 * insert_resource_expand_to_fit - Insert a resource into the resource tree
677 * @root: root resource descriptor
678 * @new: new resource to insert
679 *
680 * Insert a resource into the resource tree, possibly expanding it in order
681 * to make it encompass any conflicting resources.
682 */
683void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
684{
685 if (new->parent)
686 return;
687
688 write_lock(&resource_lock);
689 for (;;) {
690 struct resource *conflict;
691
692 conflict = __insert_resource(root, new);
693 if (!conflict)
694 break;
695 if (conflict == root)
696 break;
697
698 /* Ok, expand resource to cover the conflict, then try again .. */
699 if (conflict->start < new->start)
700 new->start = conflict->start;
701 if (conflict->end > new->end)
702 new->end = conflict->end;
703
704 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
705 }
706 write_unlock(&resource_lock);
707}
708
709/**
710 * adjust_resource - modify a resource's start and size
711 * @res: resource to modify
712 * @start: new start value
713 * @size: new size
714 *
715 * Given an existing resource, change its start and size to match the
716 * arguments. Returns 0 on success, -EBUSY if it can't fit.
717 * Existing children of the resource are assumed to be immutable.
718 */
719int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
720{
721 struct resource *tmp, *parent = res->parent;
722 resource_size_t end = start + size - 1;
723 int result = -EBUSY;
724
725 write_lock(&resource_lock);
726
727 if (!parent)
728 goto skip;
729
730 if ((start < parent->start) || (end > parent->end))
731 goto out;
732
733 if (res->sibling && (res->sibling->start <= end))
734 goto out;
735
736 tmp = parent->child;
737 if (tmp != res) {
738 while (tmp->sibling != res)
739 tmp = tmp->sibling;
740 if (start <= tmp->end)
741 goto out;
742 }
743
744skip:
745 for (tmp = res->child; tmp; tmp = tmp->sibling)
746 if ((tmp->start < start) || (tmp->end > end))
747 goto out;
748
749 res->start = start;
750 res->end = end;
751 result = 0;
752
753 out:
754 write_unlock(&resource_lock);
755 return result;
756}
757EXPORT_SYMBOL(adjust_resource);
758
759static void __init __reserve_region_with_split(struct resource *root,
760 resource_size_t start, resource_size_t end,
761 const char *name)
762{
763 struct resource *parent = root;
764 struct resource *conflict;
765 struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
766
767 if (!res)
768 return;
769
770 res->name = name;
771 res->start = start;
772 res->end = end;
773 res->flags = IORESOURCE_BUSY;
774
775 conflict = __request_resource(parent, res);
776 if (!conflict)
777 return;
778
779 /* failed, split and try again */
780 kfree(res);
781
782 /* conflict covered whole area */
783 if (conflict->start <= start && conflict->end >= end)
784 return;
785
786 if (conflict->start > start)
787 __reserve_region_with_split(root, start, conflict->start-1, name);
788 if (conflict->end < end)
789 __reserve_region_with_split(root, conflict->end+1, end, name);
790}
791
792void __init reserve_region_with_split(struct resource *root,
793 resource_size_t start, resource_size_t end,
794 const char *name)
795{
796 int abort = 0;
797
798 write_lock(&resource_lock);
799 if (root->start > start || root->end < end) {
800 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
801 (unsigned long long)start, (unsigned long long)end,
802 root);
803 if (start > root->end || end < root->start)
804 abort = 1;
805 else {
806 if (end > root->end)
807 end = root->end;
808 if (start < root->start)
809 start = root->start;
810 pr_err("fixing request to [0x%llx-0x%llx]\n",
811 (unsigned long long)start,
812 (unsigned long long)end);
813 }
814 dump_stack();
815 }
816 if (!abort)
817 __reserve_region_with_split(root, start, end, name);
818 write_unlock(&resource_lock);
819}
820
821/**
822 * resource_alignment - calculate resource's alignment
823 * @res: resource pointer
824 *
825 * Returns alignment on success, 0 (invalid alignment) on failure.
826 */
827resource_size_t resource_alignment(struct resource *res)
828{
829 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
830 case IORESOURCE_SIZEALIGN:
831 return resource_size(res);
832 case IORESOURCE_STARTALIGN:
833 return res->start;
834 default:
835 return 0;
836 }
837}
838
839/*
840 * This is compatibility stuff for IO resources.
841 *
842 * Note how this, unlike the above, knows about
843 * the IO flag meanings (busy etc).
844 *
845 * request_region creates a new busy region.
846 *
847 * check_region returns non-zero if the area is already busy.
848 *
849 * release_region releases a matching busy region.
850 */
851
852static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
853
854/**
855 * __request_region - create a new busy resource region
856 * @parent: parent resource descriptor
857 * @start: resource start address
858 * @n: resource region size
859 * @name: reserving caller's ID string
860 * @flags: IO resource flags
861 */
862struct resource * __request_region(struct resource *parent,
863 resource_size_t start, resource_size_t n,
864 const char *name, int flags)
865{
866 DECLARE_WAITQUEUE(wait, current);
867 struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
868
869 if (!res)
870 return NULL;
871
872 res->name = name;
873 res->start = start;
874 res->end = start + n - 1;
875 res->flags = IORESOURCE_BUSY;
876 res->flags |= flags;
877
878 write_lock(&resource_lock);
879
880 for (;;) {
881 struct resource *conflict;
882
883 conflict = __request_resource(parent, res);
884 if (!conflict)
885 break;
886 if (conflict != parent) {
887 parent = conflict;
888 if (!(conflict->flags & IORESOURCE_BUSY))
889 continue;
890 }
891 if (conflict->flags & flags & IORESOURCE_MUXED) {
892 add_wait_queue(&muxed_resource_wait, &wait);
893 write_unlock(&resource_lock);
894 set_current_state(TASK_UNINTERRUPTIBLE);
895 schedule();
896 remove_wait_queue(&muxed_resource_wait, &wait);
897 write_lock(&resource_lock);
898 continue;
899 }
900 /* Uhhuh, that didn't work out.. */
901 kfree(res);
902 res = NULL;
903 break;
904 }
905 write_unlock(&resource_lock);
906 return res;
907}
908EXPORT_SYMBOL(__request_region);
909
910/**
911 * __check_region - check if a resource region is busy or free
912 * @parent: parent resource descriptor
913 * @start: resource start address
914 * @n: resource region size
915 *
916 * Returns 0 if the region is free at the moment it is checked,
917 * returns %-EBUSY if the region is busy.
918 *
919 * NOTE:
920 * This function is deprecated because its use is racy.
921 * Even if it returns 0, a subsequent call to request_region()
922 * may fail because another driver etc. just allocated the region.
923 * Do NOT use it. It will be removed from the kernel.
924 */
925int __check_region(struct resource *parent, resource_size_t start,
926 resource_size_t n)
927{
928 struct resource * res;
929
930 res = __request_region(parent, start, n, "check-region", 0);
931 if (!res)
932 return -EBUSY;
933
934 release_resource(res);
935 kfree(res);
936 return 0;
937}
938EXPORT_SYMBOL(__check_region);
939
940/**
941 * __release_region - release a previously reserved resource region
942 * @parent: parent resource descriptor
943 * @start: resource start address
944 * @n: resource region size
945 *
946 * The described resource region must match a currently busy region.
947 */
948void __release_region(struct resource *parent, resource_size_t start,
949 resource_size_t n)
950{
951 struct resource **p;
952 resource_size_t end;
953
954 p = &parent->child;
955 end = start + n - 1;
956
957 write_lock(&resource_lock);
958
959 for (;;) {
960 struct resource *res = *p;
961
962 if (!res)
963 break;
964 if (res->start <= start && res->end >= end) {
965 if (!(res->flags & IORESOURCE_BUSY)) {
966 p = &res->child;
967 continue;
968 }
969 if (res->start != start || res->end != end)
970 break;
971 *p = res->sibling;
972 write_unlock(&resource_lock);
973 if (res->flags & IORESOURCE_MUXED)
974 wake_up(&muxed_resource_wait);
975 kfree(res);
976 return;
977 }
978 p = &res->sibling;
979 }
980
981 write_unlock(&resource_lock);
982
983 printk(KERN_WARNING "Trying to free nonexistent resource "
984 "<%016llx-%016llx>\n", (unsigned long long)start,
985 (unsigned long long)end);
986}
987EXPORT_SYMBOL(__release_region);
988
989/*
990 * Managed region resource
991 */
992struct region_devres {
993 struct resource *parent;
994 resource_size_t start;
995 resource_size_t n;
996};
997
998static void devm_region_release(struct device *dev, void *res)
999{
1000 struct region_devres *this = res;
1001
1002 __release_region(this->parent, this->start, this->n);
1003}
1004
1005static int devm_region_match(struct device *dev, void *res, void *match_data)
1006{
1007 struct region_devres *this = res, *match = match_data;
1008
1009 return this->parent == match->parent &&
1010 this->start == match->start && this->n == match->n;
1011}
1012
1013struct resource * __devm_request_region(struct device *dev,
1014 struct resource *parent, resource_size_t start,
1015 resource_size_t n, const char *name)
1016{
1017 struct region_devres *dr = NULL;
1018 struct resource *res;
1019
1020 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1021 GFP_KERNEL);
1022 if (!dr)
1023 return NULL;
1024
1025 dr->parent = parent;
1026 dr->start = start;
1027 dr->n = n;
1028
1029 res = __request_region(parent, start, n, name, 0);
1030 if (res)
1031 devres_add(dev, dr);
1032 else
1033 devres_free(dr);
1034
1035 return res;
1036}
1037EXPORT_SYMBOL(__devm_request_region);
1038
1039void __devm_release_region(struct device *dev, struct resource *parent,
1040 resource_size_t start, resource_size_t n)
1041{
1042 struct region_devres match_data = { parent, start, n };
1043
1044 __release_region(parent, start, n);
1045 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1046 &match_data));
1047}
1048EXPORT_SYMBOL(__devm_release_region);
1049
1050/*
1051 * Called from init/main.c to reserve IO ports.
1052 */
1053#define MAXRESERVE 4
1054static int __init reserve_setup(char *str)
1055{
1056 static int reserved;
1057 static struct resource reserve[MAXRESERVE];
1058
1059 for (;;) {
1060 unsigned int io_start, io_num;
1061 int x = reserved;
1062
1063 if (get_option (&str, &io_start) != 2)
1064 break;
1065 if (get_option (&str, &io_num) == 0)
1066 break;
1067 if (x < MAXRESERVE) {
1068 struct resource *res = reserve + x;
1069 res->name = "reserved";
1070 res->start = io_start;
1071 res->end = io_start + io_num - 1;
1072 res->flags = IORESOURCE_BUSY;
1073 res->child = NULL;
1074 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
1075 reserved = x+1;
1076 }
1077 }
1078 return 1;
1079}
1080
1081__setup("reserve=", reserve_setup);
1082
1083/*
1084 * Check if the requested addr and size spans more than any slot in the
1085 * iomem resource tree.
1086 */
1087int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1088{
1089 struct resource *p = &iomem_resource;
1090 int err = 0;
1091 loff_t l;
1092
1093 read_lock(&resource_lock);
1094 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1095 /*
1096 * We can probably skip the resources without
1097 * IORESOURCE_IO attribute?
1098 */
1099 if (p->start >= addr + size)
1100 continue;
1101 if (p->end < addr)
1102 continue;
1103 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1104 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1105 continue;
1106 /*
1107 * if a resource is "BUSY", it's not a hardware resource
1108 * but a driver mapping of such a resource; we don't want
1109 * to warn for those; some drivers legitimately map only
1110 * partial hardware resources. (example: vesafb)
1111 */
1112 if (p->flags & IORESOURCE_BUSY)
1113 continue;
1114
1115 printk(KERN_WARNING "resource map sanity check conflict: "
1116 "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
1117 (unsigned long long)addr,
1118 (unsigned long long)(addr + size - 1),
1119 (unsigned long long)p->start,
1120 (unsigned long long)p->end,
1121 p->name);
1122 err = -1;
1123 break;
1124 }
1125 read_unlock(&resource_lock);
1126
1127 return err;
1128}
1129
1130#ifdef CONFIG_STRICT_DEVMEM
1131static int strict_iomem_checks = 1;
1132#else
1133static int strict_iomem_checks;
1134#endif
1135
1136/*
1137 * check if an address is reserved in the iomem resource tree
1138 * returns 1 if reserved, 0 if not reserved.
1139 */
1140int iomem_is_exclusive(u64 addr)
1141{
1142 struct resource *p = &iomem_resource;
1143 int err = 0;
1144 loff_t l;
1145 int size = PAGE_SIZE;
1146
1147 if (!strict_iomem_checks)
1148 return 0;
1149
1150 addr = addr & PAGE_MASK;
1151
1152 read_lock(&resource_lock);
1153 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1154 /*
1155 * We can probably skip the resources without
1156 * IORESOURCE_IO attribute?
1157 */
1158 if (p->start >= addr + size)
1159 break;
1160 if (p->end < addr)
1161 continue;
1162 if (p->flags & IORESOURCE_BUSY &&
1163 p->flags & IORESOURCE_EXCLUSIVE) {
1164 err = 1;
1165 break;
1166 }
1167 }
1168 read_unlock(&resource_lock);
1169
1170 return err;
1171}
1172
1173static int __init strict_iomem(char *str)
1174{
1175 if (strstr(str, "relaxed"))
1176 strict_iomem_checks = 0;
1177 if (strstr(str, "strict"))
1178 strict_iomem_checks = 1;
1179 return 1;
1180}
1181
1182__setup("iomem=", strict_iomem);