projects/linux·blob v4.0-rc1 · 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 <linux/mm.h>
25#include <linux/resource_ext.h>
26#include <asm/io.h>
27
28
29struct resource ioport_resource = {
30 .name = "PCI IO",
31 .start = 0,
32 .end = IO_SPACE_LIMIT,
33 .flags = IORESOURCE_IO,
34};
35EXPORT_SYMBOL(ioport_resource);
36
37struct resource iomem_resource = {
38 .name = "PCI mem",
39 .start = 0,
40 .end = -1,
41 .flags = IORESOURCE_MEM,
42};
43EXPORT_SYMBOL(iomem_resource);
44
45/* constraints to be met while allocating resources */
46struct resource_constraint {
47 resource_size_t min, max, align;
48 resource_size_t (*alignf)(void *, const struct resource *,
49 resource_size_t, resource_size_t);
50 void *alignf_data;
51};
52
53static DEFINE_RWLOCK(resource_lock);
54
55/*
56 * For memory hotplug, there is no way to free resource entries allocated
57 * by boot mem after the system is up. So for reusing the resource entry
58 * we need to remember the resource.
59 */
60static struct resource *bootmem_resource_free;
61static DEFINE_SPINLOCK(bootmem_resource_lock);
62
63static struct resource *next_resource(struct resource *p, bool sibling_only)
64{
65 /* Caller wants to traverse through siblings only */
66 if (sibling_only)
67 return p->sibling;
68
69 if (p->child)
70 return p->child;
71 while (!p->sibling && p->parent)
72 p = p->parent;
73 return p->sibling;
74}
75
76static void *r_next(struct seq_file *m, void *v, loff_t *pos)
77{
78 struct resource *p = v;
79 (*pos)++;
80 return (void *)next_resource(p, false);
81}
82
83#ifdef CONFIG_PROC_FS
84
85enum { MAX_IORES_LEVEL = 5 };
86
87static void *r_start(struct seq_file *m, loff_t *pos)
88 __acquires(resource_lock)
89{
90 struct resource *p = 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
98static void r_stop(struct seq_file *m, void *v)
99 __releases(resource_lock)
100{
101 read_unlock(&resource_lock);
102}
103
104static int r_show(struct seq_file *m, void *v)
105{
106 struct resource *root = m->private;
107 struct resource *r = v, *p;
108 int width = root->end < 0x10000 ? 4 : 8;
109 int depth;
110
111 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
112 if (p->parent == root)
113 break;
114 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
115 depth * 2, "",
116 width, (unsigned long long) r->start,
117 width, (unsigned long long) r->end,
118 r->name ? r->name : "<BAD>");
119 return 0;
120}
121
122static const struct seq_operations resource_op = {
123 .start = r_start,
124 .next = r_next,
125 .stop = r_stop,
126 .show = r_show,
127};
128
129static int ioports_open(struct inode *inode, struct file *file)
130{
131 int res = seq_open(file, &resource_op);
132 if (!res) {
133 struct seq_file *m = file->private_data;
134 m->private = &ioport_resource;
135 }
136 return res;
137}
138
139static int iomem_open(struct inode *inode, struct file *file)
140{
141 int res = seq_open(file, &resource_op);
142 if (!res) {
143 struct seq_file *m = file->private_data;
144 m->private = &iomem_resource;
145 }
146 return res;
147}
148
149static const struct file_operations proc_ioports_operations = {
150 .open = ioports_open,
151 .read = seq_read,
152 .llseek = seq_lseek,
153 .release = seq_release,
154};
155
156static const struct file_operations proc_iomem_operations = {
157 .open = iomem_open,
158 .read = seq_read,
159 .llseek = seq_lseek,
160 .release = seq_release,
161};
162
163static int __init ioresources_init(void)
164{
165 proc_create("ioports", 0, NULL, &proc_ioports_operations);
166 proc_create("iomem", 0, NULL, &proc_iomem_operations);
167 return 0;
168}
169__initcall(ioresources_init);
170
171#endif /* CONFIG_PROC_FS */
172
173static void free_resource(struct resource *res)
174{
175 if (!res)
176 return;
177
178 if (!PageSlab(virt_to_head_page(res))) {
179 spin_lock(&bootmem_resource_lock);
180 res->sibling = bootmem_resource_free;
181 bootmem_resource_free = res;
182 spin_unlock(&bootmem_resource_lock);
183 } else {
184 kfree(res);
185 }
186}
187
188static struct resource *alloc_resource(gfp_t flags)
189{
190 struct resource *res = NULL;
191
192 spin_lock(&bootmem_resource_lock);
193 if (bootmem_resource_free) {
194 res = bootmem_resource_free;
195 bootmem_resource_free = res->sibling;
196 }
197 spin_unlock(&bootmem_resource_lock);
198
199 if (res)
200 memset(res, 0, sizeof(struct resource));
201 else
202 res = kzalloc(sizeof(struct resource), flags);
203
204 return res;
205}
206
207/* Return the conflict entry if you can't request it */
208static struct resource * __request_resource(struct resource *root, struct resource *new)
209{
210 resource_size_t start = new->start;
211 resource_size_t end = new->end;
212 struct resource *tmp, **p;
213
214 if (end < start)
215 return root;
216 if (start < root->start)
217 return root;
218 if (end > root->end)
219 return root;
220 p = &root->child;
221 for (;;) {
222 tmp = *p;
223 if (!tmp || tmp->start > end) {
224 new->sibling = tmp;
225 *p = new;
226 new->parent = root;
227 return NULL;
228 }
229 p = &tmp->sibling;
230 if (tmp->end < start)
231 continue;
232 return tmp;
233 }
234}
235
236static int __release_resource(struct resource *old)
237{
238 struct resource *tmp, **p;
239
240 p = &old->parent->child;
241 for (;;) {
242 tmp = *p;
243 if (!tmp)
244 break;
245 if (tmp == old) {
246 *p = tmp->sibling;
247 old->parent = NULL;
248 return 0;
249 }
250 p = &tmp->sibling;
251 }
252 return -EINVAL;
253}
254
255static void __release_child_resources(struct resource *r)
256{
257 struct resource *tmp, *p;
258 resource_size_t size;
259
260 p = r->child;
261 r->child = NULL;
262 while (p) {
263 tmp = p;
264 p = p->sibling;
265
266 tmp->parent = NULL;
267 tmp->sibling = NULL;
268 __release_child_resources(tmp);
269
270 printk(KERN_DEBUG "release child resource %pR\n", tmp);
271 /* need to restore size, and keep flags */
272 size = resource_size(tmp);
273 tmp->start = 0;
274 tmp->end = size - 1;
275 }
276}
277
278void release_child_resources(struct resource *r)
279{
280 write_lock(&resource_lock);
281 __release_child_resources(r);
282 write_unlock(&resource_lock);
283}
284
285/**
286 * request_resource_conflict - request and reserve an I/O or memory resource
287 * @root: root resource descriptor
288 * @new: resource descriptor desired by caller
289 *
290 * Returns 0 for success, conflict resource on error.
291 */
292struct resource *request_resource_conflict(struct resource *root, struct resource *new)
293{
294 struct resource *conflict;
295
296 write_lock(&resource_lock);
297 conflict = __request_resource(root, new);
298 write_unlock(&resource_lock);
299 return conflict;
300}
301
302/**
303 * request_resource - request and reserve an I/O or memory resource
304 * @root: root resource descriptor
305 * @new: resource descriptor desired by caller
306 *
307 * Returns 0 for success, negative error code on error.
308 */
309int request_resource(struct resource *root, struct resource *new)
310{
311 struct resource *conflict;
312
313 conflict = request_resource_conflict(root, new);
314 return conflict ? -EBUSY : 0;
315}
316
317EXPORT_SYMBOL(request_resource);
318
319/**
320 * release_resource - release a previously reserved resource
321 * @old: resource pointer
322 */
323int release_resource(struct resource *old)
324{
325 int retval;
326
327 write_lock(&resource_lock);
328 retval = __release_resource(old);
329 write_unlock(&resource_lock);
330 return retval;
331}
332
333EXPORT_SYMBOL(release_resource);
334
335/*
336 * Finds the lowest iomem reosurce exists with-in [res->start.res->end)
337 * the caller must specify res->start, res->end, res->flags and "name".
338 * If found, returns 0, res is overwritten, if not found, returns -1.
339 * This walks through whole tree and not just first level children
340 * until and unless first_level_children_only is true.
341 */
342static int find_next_iomem_res(struct resource *res, char *name,
343 bool first_level_children_only)
344{
345 resource_size_t start, end;
346 struct resource *p;
347 bool sibling_only = false;
348
349 BUG_ON(!res);
350
351 start = res->start;
352 end = res->end;
353 BUG_ON(start >= end);
354
355 if (first_level_children_only)
356 sibling_only = true;
357
358 read_lock(&resource_lock);
359
360 for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
361 if (p->flags != res->flags)
362 continue;
363 if (name && strcmp(p->name, name))
364 continue;
365 if (p->start > end) {
366 p = NULL;
367 break;
368 }
369 if ((p->end >= start) && (p->start < end))
370 break;
371 }
372
373 read_unlock(&resource_lock);
374 if (!p)
375 return -1;
376 /* copy data */
377 if (res->start < p->start)
378 res->start = p->start;
379 if (res->end > p->end)
380 res->end = p->end;
381 return 0;
382}
383
384/*
385 * Walks through iomem resources and calls func() with matching resource
386 * ranges. This walks through whole tree and not just first level children.
387 * All the memory ranges which overlap start,end and also match flags and
388 * name are valid candidates.
389 *
390 * @name: name of resource
391 * @flags: resource flags
392 * @start: start addr
393 * @end: end addr
394 */
395int walk_iomem_res(char *name, unsigned long flags, u64 start, u64 end,
396 void *arg, int (*func)(u64, u64, void *))
397{
398 struct resource res;
399 u64 orig_end;
400 int ret = -1;
401
402 res.start = start;
403 res.end = end;
404 res.flags = flags;
405 orig_end = res.end;
406 while ((res.start < res.end) &&
407 (!find_next_iomem_res(&res, name, false))) {
408 ret = (*func)(res.start, res.end, arg);
409 if (ret)
410 break;
411 res.start = res.end + 1;
412 res.end = orig_end;
413 }
414 return ret;
415}
416
417/*
418 * This function calls callback against all memory range of "System RAM"
419 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
420 * Now, this function is only for "System RAM". This function deals with
421 * full ranges and not pfn. If resources are not pfn aligned, dealing
422 * with pfn can truncate ranges.
423 */
424int walk_system_ram_res(u64 start, u64 end, void *arg,
425 int (*func)(u64, u64, void *))
426{
427 struct resource res;
428 u64 orig_end;
429 int ret = -1;
430
431 res.start = start;
432 res.end = end;
433 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
434 orig_end = res.end;
435 while ((res.start < res.end) &&
436 (!find_next_iomem_res(&res, "System RAM", true))) {
437 ret = (*func)(res.start, res.end, arg);
438 if (ret)
439 break;
440 res.start = res.end + 1;
441 res.end = orig_end;
442 }
443 return ret;
444}
445
446#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
447
448/*
449 * This function calls callback against all memory range of "System RAM"
450 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
451 * Now, this function is only for "System RAM".
452 */
453int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
454 void *arg, int (*func)(unsigned long, unsigned long, void *))
455{
456 struct resource res;
457 unsigned long pfn, end_pfn;
458 u64 orig_end;
459 int ret = -1;
460
461 res.start = (u64) start_pfn << PAGE_SHIFT;
462 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
463 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
464 orig_end = res.end;
465 while ((res.start < res.end) &&
466 (find_next_iomem_res(&res, "System RAM", true) >= 0)) {
467 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
468 end_pfn = (res.end + 1) >> PAGE_SHIFT;
469 if (end_pfn > pfn)
470 ret = (*func)(pfn, end_pfn - pfn, arg);
471 if (ret)
472 break;
473 res.start = res.end + 1;
474 res.end = orig_end;
475 }
476 return ret;
477}
478
479#endif
480
481static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
482{
483 return 1;
484}
485/*
486 * This generic page_is_ram() returns true if specified address is
487 * registered as "System RAM" in iomem_resource list.
488 */
489int __weak page_is_ram(unsigned long pfn)
490{
491 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
492}
493EXPORT_SYMBOL_GPL(page_is_ram);
494
495/*
496 * Search for a resouce entry that fully contains the specified region.
497 * If found, return 1 if it is RAM, 0 if not.
498 * If not found, or region is not fully contained, return -1
499 *
500 * Used by the ioremap functions to ensure the user is not remapping RAM and is
501 * a vast speed up over walking through the resource table page by page.
502 */
503int region_is_ram(resource_size_t start, unsigned long size)
504{
505 struct resource *p;
506 resource_size_t end = start + size - 1;
507 int flags = IORESOURCE_MEM | IORESOURCE_BUSY;
508 const char *name = "System RAM";
509 int ret = -1;
510
511 read_lock(&resource_lock);
512 for (p = iomem_resource.child; p ; p = p->sibling) {
513 if (end < p->start)
514 continue;
515
516 if (p->start <= start && end <= p->end) {
517 /* resource fully contains region */
518 if ((p->flags != flags) || strcmp(p->name, name))
519 ret = 0;
520 else
521 ret = 1;
522 break;
523 }
524 if (p->end < start)
525 break; /* not found */
526 }
527 read_unlock(&resource_lock);
528 return ret;
529}
530
531void __weak arch_remove_reservations(struct resource *avail)
532{
533}
534
535static resource_size_t simple_align_resource(void *data,
536 const struct resource *avail,
537 resource_size_t size,
538 resource_size_t align)
539{
540 return avail->start;
541}
542
543static void resource_clip(struct resource *res, resource_size_t min,
544 resource_size_t max)
545{
546 if (res->start < min)
547 res->start = min;
548 if (res->end > max)
549 res->end = max;
550}
551
552/*
553 * Find empty slot in the resource tree with the given range and
554 * alignment constraints
555 */
556static int __find_resource(struct resource *root, struct resource *old,
557 struct resource *new,
558 resource_size_t size,
559 struct resource_constraint *constraint)
560{
561 struct resource *this = root->child;
562 struct resource tmp = *new, avail, alloc;
563
564 tmp.start = root->start;
565 /*
566 * Skip past an allocated resource that starts at 0, since the assignment
567 * of this->start - 1 to tmp->end below would cause an underflow.
568 */
569 if (this && this->start == root->start) {
570 tmp.start = (this == old) ? old->start : this->end + 1;
571 this = this->sibling;
572 }
573 for(;;) {
574 if (this)
575 tmp.end = (this == old) ? this->end : this->start - 1;
576 else
577 tmp.end = root->end;
578
579 if (tmp.end < tmp.start)
580 goto next;
581
582 resource_clip(&tmp, constraint->min, constraint->max);
583 arch_remove_reservations(&tmp);
584
585 /* Check for overflow after ALIGN() */
586 avail.start = ALIGN(tmp.start, constraint->align);
587 avail.end = tmp.end;
588 avail.flags = new->flags & ~IORESOURCE_UNSET;
589 if (avail.start >= tmp.start) {
590 alloc.flags = avail.flags;
591 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
592 size, constraint->align);
593 alloc.end = alloc.start + size - 1;
594 if (resource_contains(&avail, &alloc)) {
595 new->start = alloc.start;
596 new->end = alloc.end;
597 return 0;
598 }
599 }
600
601next: if (!this || this->end == root->end)
602 break;
603
604 if (this != old)
605 tmp.start = this->end + 1;
606 this = this->sibling;
607 }
608 return -EBUSY;
609}
610
611/*
612 * Find empty slot in the resource tree given range and alignment.
613 */
614static int find_resource(struct resource *root, struct resource *new,
615 resource_size_t size,
616 struct resource_constraint *constraint)
617{
618 return __find_resource(root, NULL, new, size, constraint);
619}
620
621/**
622 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
623 * The resource will be relocated if the new size cannot be reallocated in the
624 * current location.
625 *
626 * @root: root resource descriptor
627 * @old: resource descriptor desired by caller
628 * @newsize: new size of the resource descriptor
629 * @constraint: the size and alignment constraints to be met.
630 */
631static int reallocate_resource(struct resource *root, struct resource *old,
632 resource_size_t newsize,
633 struct resource_constraint *constraint)
634{
635 int err=0;
636 struct resource new = *old;
637 struct resource *conflict;
638
639 write_lock(&resource_lock);
640
641 if ((err = __find_resource(root, old, &new, newsize, constraint)))
642 goto out;
643
644 if (resource_contains(&new, old)) {
645 old->start = new.start;
646 old->end = new.end;
647 goto out;
648 }
649
650 if (old->child) {
651 err = -EBUSY;
652 goto out;
653 }
654
655 if (resource_contains(old, &new)) {
656 old->start = new.start;
657 old->end = new.end;
658 } else {
659 __release_resource(old);
660 *old = new;
661 conflict = __request_resource(root, old);
662 BUG_ON(conflict);
663 }
664out:
665 write_unlock(&resource_lock);
666 return err;
667}
668
669
670/**
671 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
672 * The resource will be reallocated with a new size if it was already allocated
673 * @root: root resource descriptor
674 * @new: resource descriptor desired by caller
675 * @size: requested resource region size
676 * @min: minimum boundary to allocate
677 * @max: maximum boundary to allocate
678 * @align: alignment requested, in bytes
679 * @alignf: alignment function, optional, called if not NULL
680 * @alignf_data: arbitrary data to pass to the @alignf function
681 */
682int allocate_resource(struct resource *root, struct resource *new,
683 resource_size_t size, resource_size_t min,
684 resource_size_t max, resource_size_t align,
685 resource_size_t (*alignf)(void *,
686 const struct resource *,
687 resource_size_t,
688 resource_size_t),
689 void *alignf_data)
690{
691 int err;
692 struct resource_constraint constraint;
693
694 if (!alignf)
695 alignf = simple_align_resource;
696
697 constraint.min = min;
698 constraint.max = max;
699 constraint.align = align;
700 constraint.alignf = alignf;
701 constraint.alignf_data = alignf_data;
702
703 if ( new->parent ) {
704 /* resource is already allocated, try reallocating with
705 the new constraints */
706 return reallocate_resource(root, new, size, &constraint);
707 }
708
709 write_lock(&resource_lock);
710 err = find_resource(root, new, size, &constraint);
711 if (err >= 0 && __request_resource(root, new))
712 err = -EBUSY;
713 write_unlock(&resource_lock);
714 return err;
715}
716
717EXPORT_SYMBOL(allocate_resource);
718
719/**
720 * lookup_resource - find an existing resource by a resource start address
721 * @root: root resource descriptor
722 * @start: resource start address
723 *
724 * Returns a pointer to the resource if found, NULL otherwise
725 */
726struct resource *lookup_resource(struct resource *root, resource_size_t start)
727{
728 struct resource *res;
729
730 read_lock(&resource_lock);
731 for (res = root->child; res; res = res->sibling) {
732 if (res->start == start)
733 break;
734 }
735 read_unlock(&resource_lock);
736
737 return res;
738}
739
740/*
741 * Insert a resource into the resource tree. If successful, return NULL,
742 * otherwise return the conflicting resource (compare to __request_resource())
743 */
744static struct resource * __insert_resource(struct resource *parent, struct resource *new)
745{
746 struct resource *first, *next;
747
748 for (;; parent = first) {
749 first = __request_resource(parent, new);
750 if (!first)
751 return first;
752
753 if (first == parent)
754 return first;
755 if (WARN_ON(first == new)) /* duplicated insertion */
756 return first;
757
758 if ((first->start > new->start) || (first->end < new->end))
759 break;
760 if ((first->start == new->start) && (first->end == new->end))
761 break;
762 }
763
764 for (next = first; ; next = next->sibling) {
765 /* Partial overlap? Bad, and unfixable */
766 if (next->start < new->start || next->end > new->end)
767 return next;
768 if (!next->sibling)
769 break;
770 if (next->sibling->start > new->end)
771 break;
772 }
773
774 new->parent = parent;
775 new->sibling = next->sibling;
776 new->child = first;
777
778 next->sibling = NULL;
779 for (next = first; next; next = next->sibling)
780 next->parent = new;
781
782 if (parent->child == first) {
783 parent->child = new;
784 } else {
785 next = parent->child;
786 while (next->sibling != first)
787 next = next->sibling;
788 next->sibling = new;
789 }
790 return NULL;
791}
792
793/**
794 * insert_resource_conflict - Inserts resource in the resource tree
795 * @parent: parent of the new resource
796 * @new: new resource to insert
797 *
798 * Returns 0 on success, conflict resource if the resource can't be inserted.
799 *
800 * This function is equivalent to request_resource_conflict when no conflict
801 * happens. If a conflict happens, and the conflicting resources
802 * entirely fit within the range of the new resource, then the new
803 * resource is inserted and the conflicting resources become children of
804 * the new resource.
805 */
806struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
807{
808 struct resource *conflict;
809
810 write_lock(&resource_lock);
811 conflict = __insert_resource(parent, new);
812 write_unlock(&resource_lock);
813 return conflict;
814}
815
816/**
817 * insert_resource - Inserts a resource in the resource tree
818 * @parent: parent of the new resource
819 * @new: new resource to insert
820 *
821 * Returns 0 on success, -EBUSY if the resource can't be inserted.
822 */
823int insert_resource(struct resource *parent, struct resource *new)
824{
825 struct resource *conflict;
826
827 conflict = insert_resource_conflict(parent, new);
828 return conflict ? -EBUSY : 0;
829}
830
831/**
832 * insert_resource_expand_to_fit - Insert a resource into the resource tree
833 * @root: root resource descriptor
834 * @new: new resource to insert
835 *
836 * Insert a resource into the resource tree, possibly expanding it in order
837 * to make it encompass any conflicting resources.
838 */
839void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
840{
841 if (new->parent)
842 return;
843
844 write_lock(&resource_lock);
845 for (;;) {
846 struct resource *conflict;
847
848 conflict = __insert_resource(root, new);
849 if (!conflict)
850 break;
851 if (conflict == root)
852 break;
853
854 /* Ok, expand resource to cover the conflict, then try again .. */
855 if (conflict->start < new->start)
856 new->start = conflict->start;
857 if (conflict->end > new->end)
858 new->end = conflict->end;
859
860 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
861 }
862 write_unlock(&resource_lock);
863}
864
865static int __adjust_resource(struct resource *res, resource_size_t start,
866 resource_size_t size)
867{
868 struct resource *tmp, *parent = res->parent;
869 resource_size_t end = start + size - 1;
870 int result = -EBUSY;
871
872 if (!parent)
873 goto skip;
874
875 if ((start < parent->start) || (end > parent->end))
876 goto out;
877
878 if (res->sibling && (res->sibling->start <= end))
879 goto out;
880
881 tmp = parent->child;
882 if (tmp != res) {
883 while (tmp->sibling != res)
884 tmp = tmp->sibling;
885 if (start <= tmp->end)
886 goto out;
887 }
888
889skip:
890 for (tmp = res->child; tmp; tmp = tmp->sibling)
891 if ((tmp->start < start) || (tmp->end > end))
892 goto out;
893
894 res->start = start;
895 res->end = end;
896 result = 0;
897
898 out:
899 return result;
900}
901
902/**
903 * adjust_resource - modify a resource's start and size
904 * @res: resource to modify
905 * @start: new start value
906 * @size: new size
907 *
908 * Given an existing resource, change its start and size to match the
909 * arguments. Returns 0 on success, -EBUSY if it can't fit.
910 * Existing children of the resource are assumed to be immutable.
911 */
912int adjust_resource(struct resource *res, resource_size_t start,
913 resource_size_t size)
914{
915 int result;
916
917 write_lock(&resource_lock);
918 result = __adjust_resource(res, start, size);
919 write_unlock(&resource_lock);
920 return result;
921}
922EXPORT_SYMBOL(adjust_resource);
923
924static void __init __reserve_region_with_split(struct resource *root,
925 resource_size_t start, resource_size_t end,
926 const char *name)
927{
928 struct resource *parent = root;
929 struct resource *conflict;
930 struct resource *res = alloc_resource(GFP_ATOMIC);
931 struct resource *next_res = NULL;
932
933 if (!res)
934 return;
935
936 res->name = name;
937 res->start = start;
938 res->end = end;
939 res->flags = IORESOURCE_BUSY;
940
941 while (1) {
942
943 conflict = __request_resource(parent, res);
944 if (!conflict) {
945 if (!next_res)
946 break;
947 res = next_res;
948 next_res = NULL;
949 continue;
950 }
951
952 /* conflict covered whole area */
953 if (conflict->start <= res->start &&
954 conflict->end >= res->end) {
955 free_resource(res);
956 WARN_ON(next_res);
957 break;
958 }
959
960 /* failed, split and try again */
961 if (conflict->start > res->start) {
962 end = res->end;
963 res->end = conflict->start - 1;
964 if (conflict->end < end) {
965 next_res = alloc_resource(GFP_ATOMIC);
966 if (!next_res) {
967 free_resource(res);
968 break;
969 }
970 next_res->name = name;
971 next_res->start = conflict->end + 1;
972 next_res->end = end;
973 next_res->flags = IORESOURCE_BUSY;
974 }
975 } else {
976 res->start = conflict->end + 1;
977 }
978 }
979
980}
981
982void __init reserve_region_with_split(struct resource *root,
983 resource_size_t start, resource_size_t end,
984 const char *name)
985{
986 int abort = 0;
987
988 write_lock(&resource_lock);
989 if (root->start > start || root->end < end) {
990 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
991 (unsigned long long)start, (unsigned long long)end,
992 root);
993 if (start > root->end || end < root->start)
994 abort = 1;
995 else {
996 if (end > root->end)
997 end = root->end;
998 if (start < root->start)
999 start = root->start;
1000 pr_err("fixing request to [0x%llx-0x%llx]\n",
1001 (unsigned long long)start,
1002 (unsigned long long)end);
1003 }
1004 dump_stack();
1005 }
1006 if (!abort)
1007 __reserve_region_with_split(root, start, end, name);
1008 write_unlock(&resource_lock);
1009}
1010
1011/**
1012 * resource_alignment - calculate resource's alignment
1013 * @res: resource pointer
1014 *
1015 * Returns alignment on success, 0 (invalid alignment) on failure.
1016 */
1017resource_size_t resource_alignment(struct resource *res)
1018{
1019 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1020 case IORESOURCE_SIZEALIGN:
1021 return resource_size(res);
1022 case IORESOURCE_STARTALIGN:
1023 return res->start;
1024 default:
1025 return 0;
1026 }
1027}
1028
1029/*
1030 * This is compatibility stuff for IO resources.
1031 *
1032 * Note how this, unlike the above, knows about
1033 * the IO flag meanings (busy etc).
1034 *
1035 * request_region creates a new busy region.
1036 *
1037 * check_region returns non-zero if the area is already busy.
1038 *
1039 * release_region releases a matching busy region.
1040 */
1041
1042static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1043
1044/**
1045 * __request_region - create a new busy resource region
1046 * @parent: parent resource descriptor
1047 * @start: resource start address
1048 * @n: resource region size
1049 * @name: reserving caller's ID string
1050 * @flags: IO resource flags
1051 */
1052struct resource * __request_region(struct resource *parent,
1053 resource_size_t start, resource_size_t n,
1054 const char *name, int flags)
1055{
1056 DECLARE_WAITQUEUE(wait, current);
1057 struct resource *res = alloc_resource(GFP_KERNEL);
1058
1059 if (!res)
1060 return NULL;
1061
1062 res->name = name;
1063 res->start = start;
1064 res->end = start + n - 1;
1065 res->flags = resource_type(parent);
1066 res->flags |= IORESOURCE_BUSY | flags;
1067
1068 write_lock(&resource_lock);
1069
1070 for (;;) {
1071 struct resource *conflict;
1072
1073 conflict = __request_resource(parent, res);
1074 if (!conflict)
1075 break;
1076 if (conflict != parent) {
1077 parent = conflict;
1078 if (!(conflict->flags & IORESOURCE_BUSY))
1079 continue;
1080 }
1081 if (conflict->flags & flags & IORESOURCE_MUXED) {
1082 add_wait_queue(&muxed_resource_wait, &wait);
1083 write_unlock(&resource_lock);
1084 set_current_state(TASK_UNINTERRUPTIBLE);
1085 schedule();
1086 remove_wait_queue(&muxed_resource_wait, &wait);
1087 write_lock(&resource_lock);
1088 continue;
1089 }
1090 /* Uhhuh, that didn't work out.. */
1091 free_resource(res);
1092 res = NULL;
1093 break;
1094 }
1095 write_unlock(&resource_lock);
1096 return res;
1097}
1098EXPORT_SYMBOL(__request_region);
1099
1100/**
1101 * __check_region - check if a resource region is busy or free
1102 * @parent: parent resource descriptor
1103 * @start: resource start address
1104 * @n: resource region size
1105 *
1106 * Returns 0 if the region is free at the moment it is checked,
1107 * returns %-EBUSY if the region is busy.
1108 *
1109 * NOTE:
1110 * This function is deprecated because its use is racy.
1111 * Even if it returns 0, a subsequent call to request_region()
1112 * may fail because another driver etc. just allocated the region.
1113 * Do NOT use it. It will be removed from the kernel.
1114 */
1115int __check_region(struct resource *parent, resource_size_t start,
1116 resource_size_t n)
1117{
1118 struct resource * res;
1119
1120 res = __request_region(parent, start, n, "check-region", 0);
1121 if (!res)
1122 return -EBUSY;
1123
1124 release_resource(res);
1125 free_resource(res);
1126 return 0;
1127}
1128EXPORT_SYMBOL(__check_region);
1129
1130/**
1131 * __release_region - release a previously reserved resource region
1132 * @parent: parent resource descriptor
1133 * @start: resource start address
1134 * @n: resource region size
1135 *
1136 * The described resource region must match a currently busy region.
1137 */
1138void __release_region(struct resource *parent, resource_size_t start,
1139 resource_size_t n)
1140{
1141 struct resource **p;
1142 resource_size_t end;
1143
1144 p = &parent->child;
1145 end = start + n - 1;
1146
1147 write_lock(&resource_lock);
1148
1149 for (;;) {
1150 struct resource *res = *p;
1151
1152 if (!res)
1153 break;
1154 if (res->start <= start && res->end >= end) {
1155 if (!(res->flags & IORESOURCE_BUSY)) {
1156 p = &res->child;
1157 continue;
1158 }
1159 if (res->start != start || res->end != end)
1160 break;
1161 *p = res->sibling;
1162 write_unlock(&resource_lock);
1163 if (res->flags & IORESOURCE_MUXED)
1164 wake_up(&muxed_resource_wait);
1165 free_resource(res);
1166 return;
1167 }
1168 p = &res->sibling;
1169 }
1170
1171 write_unlock(&resource_lock);
1172
1173 printk(KERN_WARNING "Trying to free nonexistent resource "
1174 "<%016llx-%016llx>\n", (unsigned long long)start,
1175 (unsigned long long)end);
1176}
1177EXPORT_SYMBOL(__release_region);
1178
1179#ifdef CONFIG_MEMORY_HOTREMOVE
1180/**
1181 * release_mem_region_adjustable - release a previously reserved memory region
1182 * @parent: parent resource descriptor
1183 * @start: resource start address
1184 * @size: resource region size
1185 *
1186 * This interface is intended for memory hot-delete. The requested region
1187 * is released from a currently busy memory resource. The requested region
1188 * must either match exactly or fit into a single busy resource entry. In
1189 * the latter case, the remaining resource is adjusted accordingly.
1190 * Existing children of the busy memory resource must be immutable in the
1191 * request.
1192 *
1193 * Note:
1194 * - Additional release conditions, such as overlapping region, can be
1195 * supported after they are confirmed as valid cases.
1196 * - When a busy memory resource gets split into two entries, the code
1197 * assumes that all children remain in the lower address entry for
1198 * simplicity. Enhance this logic when necessary.
1199 */
1200int release_mem_region_adjustable(struct resource *parent,
1201 resource_size_t start, resource_size_t size)
1202{
1203 struct resource **p;
1204 struct resource *res;
1205 struct resource *new_res;
1206 resource_size_t end;
1207 int ret = -EINVAL;
1208
1209 end = start + size - 1;
1210 if ((start < parent->start) || (end > parent->end))
1211 return ret;
1212
1213 /* The alloc_resource() result gets checked later */
1214 new_res = alloc_resource(GFP_KERNEL);
1215
1216 p = &parent->child;
1217 write_lock(&resource_lock);
1218
1219 while ((res = *p)) {
1220 if (res->start >= end)
1221 break;
1222
1223 /* look for the next resource if it does not fit into */
1224 if (res->start > start || res->end < end) {
1225 p = &res->sibling;
1226 continue;
1227 }
1228
1229 if (!(res->flags & IORESOURCE_MEM))
1230 break;
1231
1232 if (!(res->flags & IORESOURCE_BUSY)) {
1233 p = &res->child;
1234 continue;
1235 }
1236
1237 /* found the target resource; let's adjust accordingly */
1238 if (res->start == start && res->end == end) {
1239 /* free the whole entry */
1240 *p = res->sibling;
1241 free_resource(res);
1242 ret = 0;
1243 } else if (res->start == start && res->end != end) {
1244 /* adjust the start */
1245 ret = __adjust_resource(res, end + 1,
1246 res->end - end);
1247 } else if (res->start != start && res->end == end) {
1248 /* adjust the end */
1249 ret = __adjust_resource(res, res->start,
1250 start - res->start);
1251 } else {
1252 /* split into two entries */
1253 if (!new_res) {
1254 ret = -ENOMEM;
1255 break;
1256 }
1257 new_res->name = res->name;
1258 new_res->start = end + 1;
1259 new_res->end = res->end;
1260 new_res->flags = res->flags;
1261 new_res->parent = res->parent;
1262 new_res->sibling = res->sibling;
1263 new_res->child = NULL;
1264
1265 ret = __adjust_resource(res, res->start,
1266 start - res->start);
1267 if (ret)
1268 break;
1269 res->sibling = new_res;
1270 new_res = NULL;
1271 }
1272
1273 break;
1274 }
1275
1276 write_unlock(&resource_lock);
1277 free_resource(new_res);
1278 return ret;
1279}
1280#endif /* CONFIG_MEMORY_HOTREMOVE */
1281
1282/*
1283 * Managed region resource
1284 */
1285static void devm_resource_release(struct device *dev, void *ptr)
1286{
1287 struct resource **r = ptr;
1288
1289 release_resource(*r);
1290}
1291
1292/**
1293 * devm_request_resource() - request and reserve an I/O or memory resource
1294 * @dev: device for which to request the resource
1295 * @root: root of the resource tree from which to request the resource
1296 * @new: descriptor of the resource to request
1297 *
1298 * This is a device-managed version of request_resource(). There is usually
1299 * no need to release resources requested by this function explicitly since
1300 * that will be taken care of when the device is unbound from its driver.
1301 * If for some reason the resource needs to be released explicitly, because
1302 * of ordering issues for example, drivers must call devm_release_resource()
1303 * rather than the regular release_resource().
1304 *
1305 * When a conflict is detected between any existing resources and the newly
1306 * requested resource, an error message will be printed.
1307 *
1308 * Returns 0 on success or a negative error code on failure.
1309 */
1310int devm_request_resource(struct device *dev, struct resource *root,
1311 struct resource *new)
1312{
1313 struct resource *conflict, **ptr;
1314
1315 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1316 if (!ptr)
1317 return -ENOMEM;
1318
1319 *ptr = new;
1320
1321 conflict = request_resource_conflict(root, new);
1322 if (conflict) {
1323 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1324 new, conflict->name, conflict);
1325 devres_free(ptr);
1326 return -EBUSY;
1327 }
1328
1329 devres_add(dev, ptr);
1330 return 0;
1331}
1332EXPORT_SYMBOL(devm_request_resource);
1333
1334static int devm_resource_match(struct device *dev, void *res, void *data)
1335{
1336 struct resource **ptr = res;
1337
1338 return *ptr == data;
1339}
1340
1341/**
1342 * devm_release_resource() - release a previously requested resource
1343 * @dev: device for which to release the resource
1344 * @new: descriptor of the resource to release
1345 *
1346 * Releases a resource previously requested using devm_request_resource().
1347 */
1348void devm_release_resource(struct device *dev, struct resource *new)
1349{
1350 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1351 new));
1352}
1353EXPORT_SYMBOL(devm_release_resource);
1354
1355struct region_devres {
1356 struct resource *parent;
1357 resource_size_t start;
1358 resource_size_t n;
1359};
1360
1361static void devm_region_release(struct device *dev, void *res)
1362{
1363 struct region_devres *this = res;
1364
1365 __release_region(this->parent, this->start, this->n);
1366}
1367
1368static int devm_region_match(struct device *dev, void *res, void *match_data)
1369{
1370 struct region_devres *this = res, *match = match_data;
1371
1372 return this->parent == match->parent &&
1373 this->start == match->start && this->n == match->n;
1374}
1375
1376struct resource * __devm_request_region(struct device *dev,
1377 struct resource *parent, resource_size_t start,
1378 resource_size_t n, const char *name)
1379{
1380 struct region_devres *dr = NULL;
1381 struct resource *res;
1382
1383 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1384 GFP_KERNEL);
1385 if (!dr)
1386 return NULL;
1387
1388 dr->parent = parent;
1389 dr->start = start;
1390 dr->n = n;
1391
1392 res = __request_region(parent, start, n, name, 0);
1393 if (res)
1394 devres_add(dev, dr);
1395 else
1396 devres_free(dr);
1397
1398 return res;
1399}
1400EXPORT_SYMBOL(__devm_request_region);
1401
1402void __devm_release_region(struct device *dev, struct resource *parent,
1403 resource_size_t start, resource_size_t n)
1404{
1405 struct region_devres match_data = { parent, start, n };
1406
1407 __release_region(parent, start, n);
1408 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1409 &match_data));
1410}
1411EXPORT_SYMBOL(__devm_release_region);
1412
1413/*
1414 * Called from init/main.c to reserve IO ports.
1415 */
1416#define MAXRESERVE 4
1417static int __init reserve_setup(char *str)
1418{
1419 static int reserved;
1420 static struct resource reserve[MAXRESERVE];
1421
1422 for (;;) {
1423 unsigned int io_start, io_num;
1424 int x = reserved;
1425
1426 if (get_option (&str, &io_start) != 2)
1427 break;
1428 if (get_option (&str, &io_num) == 0)
1429 break;
1430 if (x < MAXRESERVE) {
1431 struct resource *res = reserve + x;
1432 res->name = "reserved";
1433 res->start = io_start;
1434 res->end = io_start + io_num - 1;
1435 res->flags = IORESOURCE_BUSY;
1436 res->child = NULL;
1437 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
1438 reserved = x+1;
1439 }
1440 }
1441 return 1;
1442}
1443
1444__setup("reserve=", reserve_setup);
1445
1446/*
1447 * Check if the requested addr and size spans more than any slot in the
1448 * iomem resource tree.
1449 */
1450int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1451{
1452 struct resource *p = &iomem_resource;
1453 int err = 0;
1454 loff_t l;
1455
1456 read_lock(&resource_lock);
1457 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1458 /*
1459 * We can probably skip the resources without
1460 * IORESOURCE_IO attribute?
1461 */
1462 if (p->start >= addr + size)
1463 continue;
1464 if (p->end < addr)
1465 continue;
1466 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1467 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1468 continue;
1469 /*
1470 * if a resource is "BUSY", it's not a hardware resource
1471 * but a driver mapping of such a resource; we don't want
1472 * to warn for those; some drivers legitimately map only
1473 * partial hardware resources. (example: vesafb)
1474 */
1475 if (p->flags & IORESOURCE_BUSY)
1476 continue;
1477
1478 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1479 (unsigned long long)addr,
1480 (unsigned long long)(addr + size - 1),
1481 p->name, p);
1482 err = -1;
1483 break;
1484 }
1485 read_unlock(&resource_lock);
1486
1487 return err;
1488}
1489
1490#ifdef CONFIG_STRICT_DEVMEM
1491static int strict_iomem_checks = 1;
1492#else
1493static int strict_iomem_checks;
1494#endif
1495
1496/*
1497 * check if an address is reserved in the iomem resource tree
1498 * returns 1 if reserved, 0 if not reserved.
1499 */
1500int iomem_is_exclusive(u64 addr)
1501{
1502 struct resource *p = &iomem_resource;
1503 int err = 0;
1504 loff_t l;
1505 int size = PAGE_SIZE;
1506
1507 if (!strict_iomem_checks)
1508 return 0;
1509
1510 addr = addr & PAGE_MASK;
1511
1512 read_lock(&resource_lock);
1513 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1514 /*
1515 * We can probably skip the resources without
1516 * IORESOURCE_IO attribute?
1517 */
1518 if (p->start >= addr + size)
1519 break;
1520 if (p->end < addr)
1521 continue;
1522 if (p->flags & IORESOURCE_BUSY &&
1523 p->flags & IORESOURCE_EXCLUSIVE) {
1524 err = 1;
1525 break;
1526 }
1527 }
1528 read_unlock(&resource_lock);
1529
1530 return err;
1531}
1532
1533struct resource_entry *resource_list_create_entry(struct resource *res,
1534 size_t extra_size)
1535{
1536 struct resource_entry *entry;
1537
1538 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1539 if (entry) {
1540 INIT_LIST_HEAD(&entry->node);
1541 entry->res = res ? res : &entry->__res;
1542 }
1543
1544 return entry;
1545}
1546EXPORT_SYMBOL(resource_list_create_entry);
1547
1548void resource_list_free(struct list_head *head)
1549{
1550 struct resource_entry *entry, *tmp;
1551
1552 list_for_each_entry_safe(entry, tmp, head, node)
1553 resource_list_destroy_entry(entry);
1554}
1555EXPORT_SYMBOL(resource_list_free);
1556
1557static int __init strict_iomem(char *str)
1558{
1559 if (strstr(str, "relaxed"))
1560 strict_iomem_checks = 0;
1561 if (strstr(str, "strict"))
1562 strict_iomem_checks = 1;
1563 return 1;
1564}
1565
1566__setup("iomem=", strict_iomem);