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1/*
2 * linux/kernel/resource.c
3 *
4 * Copyright (C) 1999 Linus Torvalds
5 * Copyright (C) 1999 Martin Mares <mj@ucw.cz>
6 *
7 * Arbitrary resource management.
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/export.h>
13#include <linux/errno.h>
14#include <linux/ioport.h>
15#include <linux/init.h>
16#include <linux/slab.h>
17#include <linux/spinlock.h>
18#include <linux/fs.h>
19#include <linux/proc_fs.h>
20#include <linux/sched.h>
21#include <linux/seq_file.h>
22#include <linux/device.h>
23#include <linux/pfn.h>
24#include <linux/mm.h>
25#include <linux/resource_ext.h>
26#include <asm/io.h>
27
28
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 unsigned long long start, end;
109 int width = root->end < 0x10000 ? 4 : 8;
110 int depth;
111
112 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
113 if (p->parent == root)
114 break;
115
116 if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
117 start = r->start;
118 end = r->end;
119 } else {
120 start = end = 0;
121 }
122
123 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
124 depth * 2, "",
125 width, start,
126 width, end,
127 r->name ? r->name : "<BAD>");
128 return 0;
129}
130
131static const struct seq_operations resource_op = {
132 .start = r_start,
133 .next = r_next,
134 .stop = r_stop,
135 .show = r_show,
136};
137
138static int 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
148static 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
158static 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
165static 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
172static 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
182static 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
197static 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 */
217static 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
245static 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
274static 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
297void 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 */
311struct 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 */
328int 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
336EXPORT_SYMBOL(request_resource);
337
338/**
339 * release_resource - release a previously reserved resource
340 * @old: resource pointer
341 */
342int 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
352EXPORT_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 */
361static 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 res->flags = p->flags;
401 res->desc = p->desc;
402 return 0;
403}
404
405static int __walk_iomem_res_desc(struct resource *res, unsigned long desc,
406 bool first_level_children_only,
407 void *arg,
408 int (*func)(struct resource *, void *))
409{
410 u64 orig_end = res->end;
411 int ret = -1;
412
413 while ((res->start < res->end) &&
414 !find_next_iomem_res(res, desc, first_level_children_only)) {
415 ret = (*func)(res, arg);
416 if (ret)
417 break;
418
419 res->start = res->end + 1;
420 res->end = orig_end;
421 }
422
423 return ret;
424}
425
426/*
427 * Walks through iomem resources and calls func() with matching resource
428 * ranges. This walks through whole tree and not just first level children.
429 * All the memory ranges which overlap start,end and also match flags and
430 * desc are valid candidates.
431 *
432 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
433 * @flags: I/O resource flags
434 * @start: start addr
435 * @end: end addr
436 *
437 * NOTE: For a new descriptor search, define a new IORES_DESC in
438 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
439 */
440int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
441 u64 end, void *arg, int (*func)(struct resource *, void *))
442{
443 struct resource res;
444
445 res.start = start;
446 res.end = end;
447 res.flags = flags;
448
449 return __walk_iomem_res_desc(&res, desc, false, arg, func);
450}
451
452/*
453 * This function calls the @func callback against all memory ranges of type
454 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
455 * Now, this function is only for System RAM, it deals with full ranges and
456 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
457 * ranges.
458 */
459int walk_system_ram_res(u64 start, u64 end, void *arg,
460 int (*func)(struct resource *, void *))
461{
462 struct resource res;
463
464 res.start = start;
465 res.end = end;
466 res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
467
468 return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true,
469 arg, func);
470}
471
472/*
473 * This function calls the @func callback against all memory ranges, which
474 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
475 */
476int walk_mem_res(u64 start, u64 end, void *arg,
477 int (*func)(struct resource *, void *))
478{
479 struct resource res;
480
481 res.start = start;
482 res.end = end;
483 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
484
485 return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true,
486 arg, func);
487}
488
489#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
490
491/*
492 * This function calls the @func callback against all memory ranges of type
493 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
494 * It is to be used only for System RAM.
495 */
496int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
497 void *arg, int (*func)(unsigned long, unsigned long, void *))
498{
499 struct resource res;
500 unsigned long pfn, end_pfn;
501 u64 orig_end;
502 int ret = -1;
503
504 res.start = (u64) start_pfn << PAGE_SHIFT;
505 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
506 res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
507 orig_end = res.end;
508 while ((res.start < res.end) &&
509 (find_next_iomem_res(&res, IORES_DESC_NONE, true) >= 0)) {
510 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
511 end_pfn = (res.end + 1) >> PAGE_SHIFT;
512 if (end_pfn > pfn)
513 ret = (*func)(pfn, end_pfn - pfn, arg);
514 if (ret)
515 break;
516 res.start = res.end + 1;
517 res.end = orig_end;
518 }
519 return ret;
520}
521
522#endif
523
524static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
525{
526 return 1;
527}
528
529/*
530 * This generic page_is_ram() returns true if specified address is
531 * registered as System RAM in iomem_resource list.
532 */
533int __weak page_is_ram(unsigned long pfn)
534{
535 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
536}
537EXPORT_SYMBOL_GPL(page_is_ram);
538
539/**
540 * region_intersects() - determine intersection of region with known resources
541 * @start: region start address
542 * @size: size of region
543 * @flags: flags of resource (in iomem_resource)
544 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
545 *
546 * Check if the specified region partially overlaps or fully eclipses a
547 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
548 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
549 * return REGION_MIXED if the region overlaps @flags/@desc and another
550 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
551 * and no other defined resource. Note that REGION_INTERSECTS is also
552 * returned in the case when the specified region overlaps RAM and undefined
553 * memory holes.
554 *
555 * region_intersect() is used by memory remapping functions to ensure
556 * the user is not remapping RAM and is a vast speed up over walking
557 * through the resource table page by page.
558 */
559int region_intersects(resource_size_t start, size_t size, unsigned long flags,
560 unsigned long desc)
561{
562 resource_size_t end = start + size - 1;
563 int type = 0; int other = 0;
564 struct resource *p;
565
566 read_lock(&resource_lock);
567 for (p = iomem_resource.child; p ; p = p->sibling) {
568 bool is_type = (((p->flags & flags) == flags) &&
569 ((desc == IORES_DESC_NONE) ||
570 (desc == p->desc)));
571
572 if (start >= p->start && start <= p->end)
573 is_type ? type++ : other++;
574 if (end >= p->start && end <= p->end)
575 is_type ? type++ : other++;
576 if (p->start >= start && p->end <= end)
577 is_type ? type++ : other++;
578 }
579 read_unlock(&resource_lock);
580
581 if (other == 0)
582 return type ? REGION_INTERSECTS : REGION_DISJOINT;
583
584 if (type)
585 return REGION_MIXED;
586
587 return REGION_DISJOINT;
588}
589EXPORT_SYMBOL_GPL(region_intersects);
590
591void __weak arch_remove_reservations(struct resource *avail)
592{
593}
594
595static resource_size_t simple_align_resource(void *data,
596 const struct resource *avail,
597 resource_size_t size,
598 resource_size_t align)
599{
600 return avail->start;
601}
602
603static void resource_clip(struct resource *res, resource_size_t min,
604 resource_size_t max)
605{
606 if (res->start < min)
607 res->start = min;
608 if (res->end > max)
609 res->end = max;
610}
611
612/*
613 * Find empty slot in the resource tree with the given range and
614 * alignment constraints
615 */
616static int __find_resource(struct resource *root, struct resource *old,
617 struct resource *new,
618 resource_size_t size,
619 struct resource_constraint *constraint)
620{
621 struct resource *this = root->child;
622 struct resource tmp = *new, avail, alloc;
623
624 tmp.start = root->start;
625 /*
626 * Skip past an allocated resource that starts at 0, since the assignment
627 * of this->start - 1 to tmp->end below would cause an underflow.
628 */
629 if (this && this->start == root->start) {
630 tmp.start = (this == old) ? old->start : this->end + 1;
631 this = this->sibling;
632 }
633 for(;;) {
634 if (this)
635 tmp.end = (this == old) ? this->end : this->start - 1;
636 else
637 tmp.end = root->end;
638
639 if (tmp.end < tmp.start)
640 goto next;
641
642 resource_clip(&tmp, constraint->min, constraint->max);
643 arch_remove_reservations(&tmp);
644
645 /* Check for overflow after ALIGN() */
646 avail.start = ALIGN(tmp.start, constraint->align);
647 avail.end = tmp.end;
648 avail.flags = new->flags & ~IORESOURCE_UNSET;
649 if (avail.start >= tmp.start) {
650 alloc.flags = avail.flags;
651 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
652 size, constraint->align);
653 alloc.end = alloc.start + size - 1;
654 if (alloc.start <= alloc.end &&
655 resource_contains(&avail, &alloc)) {
656 new->start = alloc.start;
657 new->end = alloc.end;
658 return 0;
659 }
660 }
661
662next: if (!this || this->end == root->end)
663 break;
664
665 if (this != old)
666 tmp.start = this->end + 1;
667 this = this->sibling;
668 }
669 return -EBUSY;
670}
671
672/*
673 * Find empty slot in the resource tree given range and alignment.
674 */
675static int find_resource(struct resource *root, struct resource *new,
676 resource_size_t size,
677 struct resource_constraint *constraint)
678{
679 return __find_resource(root, NULL, new, size, constraint);
680}
681
682/**
683 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
684 * The resource will be relocated if the new size cannot be reallocated in the
685 * current location.
686 *
687 * @root: root resource descriptor
688 * @old: resource descriptor desired by caller
689 * @newsize: new size of the resource descriptor
690 * @constraint: the size and alignment constraints to be met.
691 */
692static int reallocate_resource(struct resource *root, struct resource *old,
693 resource_size_t newsize,
694 struct resource_constraint *constraint)
695{
696 int err=0;
697 struct resource new = *old;
698 struct resource *conflict;
699
700 write_lock(&resource_lock);
701
702 if ((err = __find_resource(root, old, &new, newsize, constraint)))
703 goto out;
704
705 if (resource_contains(&new, old)) {
706 old->start = new.start;
707 old->end = new.end;
708 goto out;
709 }
710
711 if (old->child) {
712 err = -EBUSY;
713 goto out;
714 }
715
716 if (resource_contains(old, &new)) {
717 old->start = new.start;
718 old->end = new.end;
719 } else {
720 __release_resource(old, true);
721 *old = new;
722 conflict = __request_resource(root, old);
723 BUG_ON(conflict);
724 }
725out:
726 write_unlock(&resource_lock);
727 return err;
728}
729
730
731/**
732 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
733 * The resource will be reallocated with a new size if it was already allocated
734 * @root: root resource descriptor
735 * @new: resource descriptor desired by caller
736 * @size: requested resource region size
737 * @min: minimum boundary to allocate
738 * @max: maximum boundary to allocate
739 * @align: alignment requested, in bytes
740 * @alignf: alignment function, optional, called if not NULL
741 * @alignf_data: arbitrary data to pass to the @alignf function
742 */
743int allocate_resource(struct resource *root, struct resource *new,
744 resource_size_t size, resource_size_t min,
745 resource_size_t max, resource_size_t align,
746 resource_size_t (*alignf)(void *,
747 const struct resource *,
748 resource_size_t,
749 resource_size_t),
750 void *alignf_data)
751{
752 int err;
753 struct resource_constraint constraint;
754
755 if (!alignf)
756 alignf = simple_align_resource;
757
758 constraint.min = min;
759 constraint.max = max;
760 constraint.align = align;
761 constraint.alignf = alignf;
762 constraint.alignf_data = alignf_data;
763
764 if ( new->parent ) {
765 /* resource is already allocated, try reallocating with
766 the new constraints */
767 return reallocate_resource(root, new, size, &constraint);
768 }
769
770 write_lock(&resource_lock);
771 err = find_resource(root, new, size, &constraint);
772 if (err >= 0 && __request_resource(root, new))
773 err = -EBUSY;
774 write_unlock(&resource_lock);
775 return err;
776}
777
778EXPORT_SYMBOL(allocate_resource);
779
780/**
781 * lookup_resource - find an existing resource by a resource start address
782 * @root: root resource descriptor
783 * @start: resource start address
784 *
785 * Returns a pointer to the resource if found, NULL otherwise
786 */
787struct resource *lookup_resource(struct resource *root, resource_size_t start)
788{
789 struct resource *res;
790
791 read_lock(&resource_lock);
792 for (res = root->child; res; res = res->sibling) {
793 if (res->start == start)
794 break;
795 }
796 read_unlock(&resource_lock);
797
798 return res;
799}
800
801/*
802 * Insert a resource into the resource tree. If successful, return NULL,
803 * otherwise return the conflicting resource (compare to __request_resource())
804 */
805static struct resource * __insert_resource(struct resource *parent, struct resource *new)
806{
807 struct resource *first, *next;
808
809 for (;; parent = first) {
810 first = __request_resource(parent, new);
811 if (!first)
812 return first;
813
814 if (first == parent)
815 return first;
816 if (WARN_ON(first == new)) /* duplicated insertion */
817 return first;
818
819 if ((first->start > new->start) || (first->end < new->end))
820 break;
821 if ((first->start == new->start) && (first->end == new->end))
822 break;
823 }
824
825 for (next = first; ; next = next->sibling) {
826 /* Partial overlap? Bad, and unfixable */
827 if (next->start < new->start || next->end > new->end)
828 return next;
829 if (!next->sibling)
830 break;
831 if (next->sibling->start > new->end)
832 break;
833 }
834
835 new->parent = parent;
836 new->sibling = next->sibling;
837 new->child = first;
838
839 next->sibling = NULL;
840 for (next = first; next; next = next->sibling)
841 next->parent = new;
842
843 if (parent->child == first) {
844 parent->child = new;
845 } else {
846 next = parent->child;
847 while (next->sibling != first)
848 next = next->sibling;
849 next->sibling = new;
850 }
851 return NULL;
852}
853
854/**
855 * insert_resource_conflict - Inserts resource in the resource tree
856 * @parent: parent of the new resource
857 * @new: new resource to insert
858 *
859 * Returns 0 on success, conflict resource if the resource can't be inserted.
860 *
861 * This function is equivalent to request_resource_conflict when no conflict
862 * happens. If a conflict happens, and the conflicting resources
863 * entirely fit within the range of the new resource, then the new
864 * resource is inserted and the conflicting resources become children of
865 * the new resource.
866 *
867 * This function is intended for producers of resources, such as FW modules
868 * and bus drivers.
869 */
870struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
871{
872 struct resource *conflict;
873
874 write_lock(&resource_lock);
875 conflict = __insert_resource(parent, new);
876 write_unlock(&resource_lock);
877 return conflict;
878}
879
880/**
881 * insert_resource - Inserts a resource in the resource tree
882 * @parent: parent of the new resource
883 * @new: new resource to insert
884 *
885 * Returns 0 on success, -EBUSY if the resource can't be inserted.
886 *
887 * This function is intended for producers of resources, such as FW modules
888 * and bus drivers.
889 */
890int insert_resource(struct resource *parent, struct resource *new)
891{
892 struct resource *conflict;
893
894 conflict = insert_resource_conflict(parent, new);
895 return conflict ? -EBUSY : 0;
896}
897EXPORT_SYMBOL_GPL(insert_resource);
898
899/**
900 * insert_resource_expand_to_fit - Insert a resource into the resource tree
901 * @root: root resource descriptor
902 * @new: new resource to insert
903 *
904 * Insert a resource into the resource tree, possibly expanding it in order
905 * to make it encompass any conflicting resources.
906 */
907void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
908{
909 if (new->parent)
910 return;
911
912 write_lock(&resource_lock);
913 for (;;) {
914 struct resource *conflict;
915
916 conflict = __insert_resource(root, new);
917 if (!conflict)
918 break;
919 if (conflict == root)
920 break;
921
922 /* Ok, expand resource to cover the conflict, then try again .. */
923 if (conflict->start < new->start)
924 new->start = conflict->start;
925 if (conflict->end > new->end)
926 new->end = conflict->end;
927
928 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
929 }
930 write_unlock(&resource_lock);
931}
932
933/**
934 * remove_resource - Remove a resource in the resource tree
935 * @old: resource to remove
936 *
937 * Returns 0 on success, -EINVAL if the resource is not valid.
938 *
939 * This function removes a resource previously inserted by insert_resource()
940 * or insert_resource_conflict(), and moves the children (if any) up to
941 * where they were before. insert_resource() and insert_resource_conflict()
942 * insert a new resource, and move any conflicting resources down to the
943 * children of the new resource.
944 *
945 * insert_resource(), insert_resource_conflict() and remove_resource() are
946 * intended for producers of resources, such as FW modules and bus drivers.
947 */
948int remove_resource(struct resource *old)
949{
950 int retval;
951
952 write_lock(&resource_lock);
953 retval = __release_resource(old, false);
954 write_unlock(&resource_lock);
955 return retval;
956}
957EXPORT_SYMBOL_GPL(remove_resource);
958
959static int __adjust_resource(struct resource *res, resource_size_t start,
960 resource_size_t size)
961{
962 struct resource *tmp, *parent = res->parent;
963 resource_size_t end = start + size - 1;
964 int result = -EBUSY;
965
966 if (!parent)
967 goto skip;
968
969 if ((start < parent->start) || (end > parent->end))
970 goto out;
971
972 if (res->sibling && (res->sibling->start <= end))
973 goto out;
974
975 tmp = parent->child;
976 if (tmp != res) {
977 while (tmp->sibling != res)
978 tmp = tmp->sibling;
979 if (start <= tmp->end)
980 goto out;
981 }
982
983skip:
984 for (tmp = res->child; tmp; tmp = tmp->sibling)
985 if ((tmp->start < start) || (tmp->end > end))
986 goto out;
987
988 res->start = start;
989 res->end = end;
990 result = 0;
991
992 out:
993 return result;
994}
995
996/**
997 * adjust_resource - modify a resource's start and size
998 * @res: resource to modify
999 * @start: new start value
1000 * @size: new size
1001 *
1002 * Given an existing resource, change its start and size to match the
1003 * arguments. Returns 0 on success, -EBUSY if it can't fit.
1004 * Existing children of the resource are assumed to be immutable.
1005 */
1006int adjust_resource(struct resource *res, resource_size_t start,
1007 resource_size_t size)
1008{
1009 int result;
1010
1011 write_lock(&resource_lock);
1012 result = __adjust_resource(res, start, size);
1013 write_unlock(&resource_lock);
1014 return result;
1015}
1016EXPORT_SYMBOL(adjust_resource);
1017
1018static void __init __reserve_region_with_split(struct resource *root,
1019 resource_size_t start, resource_size_t end,
1020 const char *name)
1021{
1022 struct resource *parent = root;
1023 struct resource *conflict;
1024 struct resource *res = alloc_resource(GFP_ATOMIC);
1025 struct resource *next_res = NULL;
1026 int type = resource_type(root);
1027
1028 if (!res)
1029 return;
1030
1031 res->name = name;
1032 res->start = start;
1033 res->end = end;
1034 res->flags = type | IORESOURCE_BUSY;
1035 res->desc = IORES_DESC_NONE;
1036
1037 while (1) {
1038
1039 conflict = __request_resource(parent, res);
1040 if (!conflict) {
1041 if (!next_res)
1042 break;
1043 res = next_res;
1044 next_res = NULL;
1045 continue;
1046 }
1047
1048 /* conflict covered whole area */
1049 if (conflict->start <= res->start &&
1050 conflict->end >= res->end) {
1051 free_resource(res);
1052 WARN_ON(next_res);
1053 break;
1054 }
1055
1056 /* failed, split and try again */
1057 if (conflict->start > res->start) {
1058 end = res->end;
1059 res->end = conflict->start - 1;
1060 if (conflict->end < end) {
1061 next_res = alloc_resource(GFP_ATOMIC);
1062 if (!next_res) {
1063 free_resource(res);
1064 break;
1065 }
1066 next_res->name = name;
1067 next_res->start = conflict->end + 1;
1068 next_res->end = end;
1069 next_res->flags = type | IORESOURCE_BUSY;
1070 next_res->desc = IORES_DESC_NONE;
1071 }
1072 } else {
1073 res->start = conflict->end + 1;
1074 }
1075 }
1076
1077}
1078
1079void __init reserve_region_with_split(struct resource *root,
1080 resource_size_t start, resource_size_t end,
1081 const char *name)
1082{
1083 int abort = 0;
1084
1085 write_lock(&resource_lock);
1086 if (root->start > start || root->end < end) {
1087 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1088 (unsigned long long)start, (unsigned long long)end,
1089 root);
1090 if (start > root->end || end < root->start)
1091 abort = 1;
1092 else {
1093 if (end > root->end)
1094 end = root->end;
1095 if (start < root->start)
1096 start = root->start;
1097 pr_err("fixing request to [0x%llx-0x%llx]\n",
1098 (unsigned long long)start,
1099 (unsigned long long)end);
1100 }
1101 dump_stack();
1102 }
1103 if (!abort)
1104 __reserve_region_with_split(root, start, end, name);
1105 write_unlock(&resource_lock);
1106}
1107
1108/**
1109 * resource_alignment - calculate resource's alignment
1110 * @res: resource pointer
1111 *
1112 * Returns alignment on success, 0 (invalid alignment) on failure.
1113 */
1114resource_size_t resource_alignment(struct resource *res)
1115{
1116 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1117 case IORESOURCE_SIZEALIGN:
1118 return resource_size(res);
1119 case IORESOURCE_STARTALIGN:
1120 return res->start;
1121 default:
1122 return 0;
1123 }
1124}
1125
1126/*
1127 * This is compatibility stuff for IO resources.
1128 *
1129 * Note how this, unlike the above, knows about
1130 * the IO flag meanings (busy etc).
1131 *
1132 * request_region creates a new busy region.
1133 *
1134 * release_region releases a matching busy region.
1135 */
1136
1137static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1138
1139/**
1140 * __request_region - create a new busy resource region
1141 * @parent: parent resource descriptor
1142 * @start: resource start address
1143 * @n: resource region size
1144 * @name: reserving caller's ID string
1145 * @flags: IO resource flags
1146 */
1147struct resource * __request_region(struct resource *parent,
1148 resource_size_t start, resource_size_t n,
1149 const char *name, int flags)
1150{
1151 DECLARE_WAITQUEUE(wait, current);
1152 struct resource *res = alloc_resource(GFP_KERNEL);
1153
1154 if (!res)
1155 return NULL;
1156
1157 res->name = name;
1158 res->start = start;
1159 res->end = start + n - 1;
1160
1161 write_lock(&resource_lock);
1162
1163 for (;;) {
1164 struct resource *conflict;
1165
1166 res->flags = resource_type(parent) | resource_ext_type(parent);
1167 res->flags |= IORESOURCE_BUSY | flags;
1168 res->desc = parent->desc;
1169
1170 conflict = __request_resource(parent, res);
1171 if (!conflict)
1172 break;
1173 if (conflict != parent) {
1174 if (!(conflict->flags & IORESOURCE_BUSY)) {
1175 parent = conflict;
1176 continue;
1177 }
1178 }
1179 if (conflict->flags & flags & IORESOURCE_MUXED) {
1180 add_wait_queue(&muxed_resource_wait, &wait);
1181 write_unlock(&resource_lock);
1182 set_current_state(TASK_UNINTERRUPTIBLE);
1183 schedule();
1184 remove_wait_queue(&muxed_resource_wait, &wait);
1185 write_lock(&resource_lock);
1186 continue;
1187 }
1188 /* Uhhuh, that didn't work out.. */
1189 free_resource(res);
1190 res = NULL;
1191 break;
1192 }
1193 write_unlock(&resource_lock);
1194 return res;
1195}
1196EXPORT_SYMBOL(__request_region);
1197
1198/**
1199 * __release_region - release a previously reserved resource region
1200 * @parent: parent resource descriptor
1201 * @start: resource start address
1202 * @n: resource region size
1203 *
1204 * The described resource region must match a currently busy region.
1205 */
1206void __release_region(struct resource *parent, resource_size_t start,
1207 resource_size_t n)
1208{
1209 struct resource **p;
1210 resource_size_t end;
1211
1212 p = &parent->child;
1213 end = start + n - 1;
1214
1215 write_lock(&resource_lock);
1216
1217 for (;;) {
1218 struct resource *res = *p;
1219
1220 if (!res)
1221 break;
1222 if (res->start <= start && res->end >= end) {
1223 if (!(res->flags & IORESOURCE_BUSY)) {
1224 p = &res->child;
1225 continue;
1226 }
1227 if (res->start != start || res->end != end)
1228 break;
1229 *p = res->sibling;
1230 write_unlock(&resource_lock);
1231 if (res->flags & IORESOURCE_MUXED)
1232 wake_up(&muxed_resource_wait);
1233 free_resource(res);
1234 return;
1235 }
1236 p = &res->sibling;
1237 }
1238
1239 write_unlock(&resource_lock);
1240
1241 printk(KERN_WARNING "Trying to free nonexistent resource "
1242 "<%016llx-%016llx>\n", (unsigned long long)start,
1243 (unsigned long long)end);
1244}
1245EXPORT_SYMBOL(__release_region);
1246
1247#ifdef CONFIG_MEMORY_HOTREMOVE
1248/**
1249 * release_mem_region_adjustable - release a previously reserved memory region
1250 * @parent: parent resource descriptor
1251 * @start: resource start address
1252 * @size: resource region size
1253 *
1254 * This interface is intended for memory hot-delete. The requested region
1255 * is released from a currently busy memory resource. The requested region
1256 * must either match exactly or fit into a single busy resource entry. In
1257 * the latter case, the remaining resource is adjusted accordingly.
1258 * Existing children of the busy memory resource must be immutable in the
1259 * request.
1260 *
1261 * Note:
1262 * - Additional release conditions, such as overlapping region, can be
1263 * supported after they are confirmed as valid cases.
1264 * - When a busy memory resource gets split into two entries, the code
1265 * assumes that all children remain in the lower address entry for
1266 * simplicity. Enhance this logic when necessary.
1267 */
1268int release_mem_region_adjustable(struct resource *parent,
1269 resource_size_t start, resource_size_t size)
1270{
1271 struct resource **p;
1272 struct resource *res;
1273 struct resource *new_res;
1274 resource_size_t end;
1275 int ret = -EINVAL;
1276
1277 end = start + size - 1;
1278 if ((start < parent->start) || (end > parent->end))
1279 return ret;
1280
1281 /* The alloc_resource() result gets checked later */
1282 new_res = alloc_resource(GFP_KERNEL);
1283
1284 p = &parent->child;
1285 write_lock(&resource_lock);
1286
1287 while ((res = *p)) {
1288 if (res->start >= end)
1289 break;
1290
1291 /* look for the next resource if it does not fit into */
1292 if (res->start > start || res->end < end) {
1293 p = &res->sibling;
1294 continue;
1295 }
1296
1297 if (!(res->flags & IORESOURCE_MEM))
1298 break;
1299
1300 if (!(res->flags & IORESOURCE_BUSY)) {
1301 p = &res->child;
1302 continue;
1303 }
1304
1305 /* found the target resource; let's adjust accordingly */
1306 if (res->start == start && res->end == end) {
1307 /* free the whole entry */
1308 *p = res->sibling;
1309 free_resource(res);
1310 ret = 0;
1311 } else if (res->start == start && res->end != end) {
1312 /* adjust the start */
1313 ret = __adjust_resource(res, end + 1,
1314 res->end - end);
1315 } else if (res->start != start && res->end == end) {
1316 /* adjust the end */
1317 ret = __adjust_resource(res, res->start,
1318 start - res->start);
1319 } else {
1320 /* split into two entries */
1321 if (!new_res) {
1322 ret = -ENOMEM;
1323 break;
1324 }
1325 new_res->name = res->name;
1326 new_res->start = end + 1;
1327 new_res->end = res->end;
1328 new_res->flags = res->flags;
1329 new_res->desc = res->desc;
1330 new_res->parent = res->parent;
1331 new_res->sibling = res->sibling;
1332 new_res->child = NULL;
1333
1334 ret = __adjust_resource(res, res->start,
1335 start - res->start);
1336 if (ret)
1337 break;
1338 res->sibling = new_res;
1339 new_res = NULL;
1340 }
1341
1342 break;
1343 }
1344
1345 write_unlock(&resource_lock);
1346 free_resource(new_res);
1347 return ret;
1348}
1349#endif /* CONFIG_MEMORY_HOTREMOVE */
1350
1351/*
1352 * Managed region resource
1353 */
1354static void devm_resource_release(struct device *dev, void *ptr)
1355{
1356 struct resource **r = ptr;
1357
1358 release_resource(*r);
1359}
1360
1361/**
1362 * devm_request_resource() - request and reserve an I/O or memory resource
1363 * @dev: device for which to request the resource
1364 * @root: root of the resource tree from which to request the resource
1365 * @new: descriptor of the resource to request
1366 *
1367 * This is a device-managed version of request_resource(). There is usually
1368 * no need to release resources requested by this function explicitly since
1369 * that will be taken care of when the device is unbound from its driver.
1370 * If for some reason the resource needs to be released explicitly, because
1371 * of ordering issues for example, drivers must call devm_release_resource()
1372 * rather than the regular release_resource().
1373 *
1374 * When a conflict is detected between any existing resources and the newly
1375 * requested resource, an error message will be printed.
1376 *
1377 * Returns 0 on success or a negative error code on failure.
1378 */
1379int devm_request_resource(struct device *dev, struct resource *root,
1380 struct resource *new)
1381{
1382 struct resource *conflict, **ptr;
1383
1384 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1385 if (!ptr)
1386 return -ENOMEM;
1387
1388 *ptr = new;
1389
1390 conflict = request_resource_conflict(root, new);
1391 if (conflict) {
1392 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1393 new, conflict->name, conflict);
1394 devres_free(ptr);
1395 return -EBUSY;
1396 }
1397
1398 devres_add(dev, ptr);
1399 return 0;
1400}
1401EXPORT_SYMBOL(devm_request_resource);
1402
1403static int devm_resource_match(struct device *dev, void *res, void *data)
1404{
1405 struct resource **ptr = res;
1406
1407 return *ptr == data;
1408}
1409
1410/**
1411 * devm_release_resource() - release a previously requested resource
1412 * @dev: device for which to release the resource
1413 * @new: descriptor of the resource to release
1414 *
1415 * Releases a resource previously requested using devm_request_resource().
1416 */
1417void devm_release_resource(struct device *dev, struct resource *new)
1418{
1419 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1420 new));
1421}
1422EXPORT_SYMBOL(devm_release_resource);
1423
1424struct region_devres {
1425 struct resource *parent;
1426 resource_size_t start;
1427 resource_size_t n;
1428};
1429
1430static void devm_region_release(struct device *dev, void *res)
1431{
1432 struct region_devres *this = res;
1433
1434 __release_region(this->parent, this->start, this->n);
1435}
1436
1437static int devm_region_match(struct device *dev, void *res, void *match_data)
1438{
1439 struct region_devres *this = res, *match = match_data;
1440
1441 return this->parent == match->parent &&
1442 this->start == match->start && this->n == match->n;
1443}
1444
1445struct resource * __devm_request_region(struct device *dev,
1446 struct resource *parent, resource_size_t start,
1447 resource_size_t n, const char *name)
1448{
1449 struct region_devres *dr = NULL;
1450 struct resource *res;
1451
1452 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1453 GFP_KERNEL);
1454 if (!dr)
1455 return NULL;
1456
1457 dr->parent = parent;
1458 dr->start = start;
1459 dr->n = n;
1460
1461 res = __request_region(parent, start, n, name, 0);
1462 if (res)
1463 devres_add(dev, dr);
1464 else
1465 devres_free(dr);
1466
1467 return res;
1468}
1469EXPORT_SYMBOL(__devm_request_region);
1470
1471void __devm_release_region(struct device *dev, struct resource *parent,
1472 resource_size_t start, resource_size_t n)
1473{
1474 struct region_devres match_data = { parent, start, n };
1475
1476 __release_region(parent, start, n);
1477 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1478 &match_data));
1479}
1480EXPORT_SYMBOL(__devm_release_region);
1481
1482/*
1483 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1484 */
1485#define MAXRESERVE 4
1486static int __init reserve_setup(char *str)
1487{
1488 static int reserved;
1489 static struct resource reserve[MAXRESERVE];
1490
1491 for (;;) {
1492 unsigned int io_start, io_num;
1493 int x = reserved;
1494 struct resource *parent;
1495
1496 if (get_option(&str, &io_start) != 2)
1497 break;
1498 if (get_option(&str, &io_num) == 0)
1499 break;
1500 if (x < MAXRESERVE) {
1501 struct resource *res = reserve + x;
1502
1503 /*
1504 * If the region starts below 0x10000, we assume it's
1505 * I/O port space; otherwise assume it's memory.
1506 */
1507 if (io_start < 0x10000) {
1508 res->flags = IORESOURCE_IO;
1509 parent = &ioport_resource;
1510 } else {
1511 res->flags = IORESOURCE_MEM;
1512 parent = &iomem_resource;
1513 }
1514 res->name = "reserved";
1515 res->start = io_start;
1516 res->end = io_start + io_num - 1;
1517 res->flags |= IORESOURCE_BUSY;
1518 res->desc = IORES_DESC_NONE;
1519 res->child = NULL;
1520 if (request_resource(parent, res) == 0)
1521 reserved = x+1;
1522 }
1523 }
1524 return 1;
1525}
1526__setup("reserve=", reserve_setup);
1527
1528/*
1529 * Check if the requested addr and size spans more than any slot in the
1530 * iomem resource tree.
1531 */
1532int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1533{
1534 struct resource *p = &iomem_resource;
1535 int err = 0;
1536 loff_t l;
1537
1538 read_lock(&resource_lock);
1539 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1540 /*
1541 * We can probably skip the resources without
1542 * IORESOURCE_IO attribute?
1543 */
1544 if (p->start >= addr + size)
1545 continue;
1546 if (p->end < addr)
1547 continue;
1548 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1549 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1550 continue;
1551 /*
1552 * if a resource is "BUSY", it's not a hardware resource
1553 * but a driver mapping of such a resource; we don't want
1554 * to warn for those; some drivers legitimately map only
1555 * partial hardware resources. (example: vesafb)
1556 */
1557 if (p->flags & IORESOURCE_BUSY)
1558 continue;
1559
1560 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1561 (unsigned long long)addr,
1562 (unsigned long long)(addr + size - 1),
1563 p->name, p);
1564 err = -1;
1565 break;
1566 }
1567 read_unlock(&resource_lock);
1568
1569 return err;
1570}
1571
1572#ifdef CONFIG_STRICT_DEVMEM
1573static int strict_iomem_checks = 1;
1574#else
1575static int strict_iomem_checks;
1576#endif
1577
1578/*
1579 * check if an address is reserved in the iomem resource tree
1580 * returns true if reserved, false if not reserved.
1581 */
1582bool iomem_is_exclusive(u64 addr)
1583{
1584 struct resource *p = &iomem_resource;
1585 bool err = false;
1586 loff_t l;
1587 int size = PAGE_SIZE;
1588
1589 if (!strict_iomem_checks)
1590 return false;
1591
1592 addr = addr & PAGE_MASK;
1593
1594 read_lock(&resource_lock);
1595 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1596 /*
1597 * We can probably skip the resources without
1598 * IORESOURCE_IO attribute?
1599 */
1600 if (p->start >= addr + size)
1601 break;
1602 if (p->end < addr)
1603 continue;
1604 /*
1605 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1606 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1607 * resource is busy.
1608 */
1609 if ((p->flags & IORESOURCE_BUSY) == 0)
1610 continue;
1611 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1612 || p->flags & IORESOURCE_EXCLUSIVE) {
1613 err = true;
1614 break;
1615 }
1616 }
1617 read_unlock(&resource_lock);
1618
1619 return err;
1620}
1621
1622struct resource_entry *resource_list_create_entry(struct resource *res,
1623 size_t extra_size)
1624{
1625 struct resource_entry *entry;
1626
1627 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1628 if (entry) {
1629 INIT_LIST_HEAD(&entry->node);
1630 entry->res = res ? res : &entry->__res;
1631 }
1632
1633 return entry;
1634}
1635EXPORT_SYMBOL(resource_list_create_entry);
1636
1637void resource_list_free(struct list_head *head)
1638{
1639 struct resource_entry *entry, *tmp;
1640
1641 list_for_each_entry_safe(entry, tmp, head, node)
1642 resource_list_destroy_entry(entry);
1643}
1644EXPORT_SYMBOL(resource_list_free);
1645
1646static int __init strict_iomem(char *str)
1647{
1648 if (strstr(str, "relaxed"))
1649 strict_iomem_checks = 0;
1650 if (strstr(str, "strict"))
1651 strict_iomem_checks = 1;
1652 return 1;
1653}
1654
1655__setup("iomem=", strict_iomem);
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#include <linux/export.h>
11#include <linux/errno.h>
12#include <linux/ioport.h>
13#include <linux/init.h>
14#include <linux/slab.h>
15#include <linux/spinlock.h>
16#include <linux/fs.h>
17#include <linux/proc_fs.h>
18#include <linux/sched.h>
19#include <linux/seq_file.h>
20#include <linux/device.h>
21#include <linux/pfn.h>
22#include <asm/io.h>
23
24
25struct resource ioport_resource = {
26 .name = "PCI IO",
27 .start = 0,
28 .end = IO_SPACE_LIMIT,
29 .flags = IORESOURCE_IO,
30};
31EXPORT_SYMBOL(ioport_resource);
32
33struct resource iomem_resource = {
34 .name = "PCI mem",
35 .start = 0,
36 .end = -1,
37 .flags = IORESOURCE_MEM,
38};
39EXPORT_SYMBOL(iomem_resource);
40
41/* constraints to be met while allocating resources */
42struct resource_constraint {
43 resource_size_t min, max, align;
44 resource_size_t (*alignf)(void *, const struct resource *,
45 resource_size_t, resource_size_t);
46 void *alignf_data;
47};
48
49static DEFINE_RWLOCK(resource_lock);
50
51static void *r_next(struct seq_file *m, void *v, loff_t *pos)
52{
53 struct resource *p = v;
54 (*pos)++;
55 if (p->child)
56 return p->child;
57 while (!p->sibling && p->parent)
58 p = p->parent;
59 return p->sibling;
60}
61
62#ifdef CONFIG_PROC_FS
63
64enum { MAX_IORES_LEVEL = 5 };
65
66static void *r_start(struct seq_file *m, loff_t *pos)
67 __acquires(resource_lock)
68{
69 struct resource *p = m->private;
70 loff_t l = 0;
71 read_lock(&resource_lock);
72 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
73 ;
74 return p;
75}
76
77static void r_stop(struct seq_file *m, void *v)
78 __releases(resource_lock)
79{
80 read_unlock(&resource_lock);
81}
82
83static int r_show(struct seq_file *m, void *v)
84{
85 struct resource *root = m->private;
86 struct resource *r = v, *p;
87 int width = root->end < 0x10000 ? 4 : 8;
88 int depth;
89
90 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
91 if (p->parent == root)
92 break;
93 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
94 depth * 2, "",
95 width, (unsigned long long) r->start,
96 width, (unsigned long long) r->end,
97 r->name ? r->name : "<BAD>");
98 return 0;
99}
100
101static const struct seq_operations resource_op = {
102 .start = r_start,
103 .next = r_next,
104 .stop = r_stop,
105 .show = r_show,
106};
107
108static int ioports_open(struct inode *inode, struct file *file)
109{
110 int res = seq_open(file, &resource_op);
111 if (!res) {
112 struct seq_file *m = file->private_data;
113 m->private = &ioport_resource;
114 }
115 return res;
116}
117
118static int iomem_open(struct inode *inode, struct file *file)
119{
120 int res = seq_open(file, &resource_op);
121 if (!res) {
122 struct seq_file *m = file->private_data;
123 m->private = &iomem_resource;
124 }
125 return res;
126}
127
128static const struct file_operations proc_ioports_operations = {
129 .open = ioports_open,
130 .read = seq_read,
131 .llseek = seq_lseek,
132 .release = seq_release,
133};
134
135static const struct file_operations proc_iomem_operations = {
136 .open = iomem_open,
137 .read = seq_read,
138 .llseek = seq_lseek,
139 .release = seq_release,
140};
141
142static int __init ioresources_init(void)
143{
144 proc_create("ioports", 0, NULL, &proc_ioports_operations);
145 proc_create("iomem", 0, NULL, &proc_iomem_operations);
146 return 0;
147}
148__initcall(ioresources_init);
149
150#endif /* CONFIG_PROC_FS */
151
152/* Return the conflict entry if you can't request it */
153static struct resource * __request_resource(struct resource *root, struct resource *new)
154{
155 resource_size_t start = new->start;
156 resource_size_t end = new->end;
157 struct resource *tmp, **p;
158
159 if (end < start)
160 return root;
161 if (start < root->start)
162 return root;
163 if (end > root->end)
164 return root;
165 p = &root->child;
166 for (;;) {
167 tmp = *p;
168 if (!tmp || tmp->start > end) {
169 new->sibling = tmp;
170 *p = new;
171 new->parent = root;
172 return NULL;
173 }
174 p = &tmp->sibling;
175 if (tmp->end < start)
176 continue;
177 return tmp;
178 }
179}
180
181static int __release_resource(struct resource *old)
182{
183 struct resource *tmp, **p;
184
185 p = &old->parent->child;
186 for (;;) {
187 tmp = *p;
188 if (!tmp)
189 break;
190 if (tmp == old) {
191 *p = tmp->sibling;
192 old->parent = NULL;
193 return 0;
194 }
195 p = &tmp->sibling;
196 }
197 return -EINVAL;
198}
199
200static void __release_child_resources(struct resource *r)
201{
202 struct resource *tmp, *p;
203 resource_size_t size;
204
205 p = r->child;
206 r->child = NULL;
207 while (p) {
208 tmp = p;
209 p = p->sibling;
210
211 tmp->parent = NULL;
212 tmp->sibling = NULL;
213 __release_child_resources(tmp);
214
215 printk(KERN_DEBUG "release child resource %pR\n", tmp);
216 /* need to restore size, and keep flags */
217 size = resource_size(tmp);
218 tmp->start = 0;
219 tmp->end = size - 1;
220 }
221}
222
223void release_child_resources(struct resource *r)
224{
225 write_lock(&resource_lock);
226 __release_child_resources(r);
227 write_unlock(&resource_lock);
228}
229
230/**
231 * request_resource_conflict - request and reserve an I/O or memory resource
232 * @root: root resource descriptor
233 * @new: resource descriptor desired by caller
234 *
235 * Returns 0 for success, conflict resource on error.
236 */
237struct resource *request_resource_conflict(struct resource *root, struct resource *new)
238{
239 struct resource *conflict;
240
241 write_lock(&resource_lock);
242 conflict = __request_resource(root, new);
243 write_unlock(&resource_lock);
244 return conflict;
245}
246
247/**
248 * request_resource - request and reserve an I/O or memory resource
249 * @root: root resource descriptor
250 * @new: resource descriptor desired by caller
251 *
252 * Returns 0 for success, negative error code on error.
253 */
254int request_resource(struct resource *root, struct resource *new)
255{
256 struct resource *conflict;
257
258 conflict = request_resource_conflict(root, new);
259 return conflict ? -EBUSY : 0;
260}
261
262EXPORT_SYMBOL(request_resource);
263
264/**
265 * release_resource - release a previously reserved resource
266 * @old: resource pointer
267 */
268int release_resource(struct resource *old)
269{
270 int retval;
271
272 write_lock(&resource_lock);
273 retval = __release_resource(old);
274 write_unlock(&resource_lock);
275 return retval;
276}
277
278EXPORT_SYMBOL(release_resource);
279
280#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
281/*
282 * Finds the lowest memory reosurce exists within [res->start.res->end)
283 * the caller must specify res->start, res->end, res->flags and "name".
284 * If found, returns 0, res is overwritten, if not found, returns -1.
285 */
286static int find_next_system_ram(struct resource *res, char *name)
287{
288 resource_size_t start, end;
289 struct resource *p;
290
291 BUG_ON(!res);
292
293 start = res->start;
294 end = res->end;
295 BUG_ON(start >= end);
296
297 read_lock(&resource_lock);
298 for (p = iomem_resource.child; p ; p = p->sibling) {
299 /* system ram is just marked as IORESOURCE_MEM */
300 if (p->flags != res->flags)
301 continue;
302 if (name && strcmp(p->name, name))
303 continue;
304 if (p->start > end) {
305 p = NULL;
306 break;
307 }
308 if ((p->end >= start) && (p->start < end))
309 break;
310 }
311 read_unlock(&resource_lock);
312 if (!p)
313 return -1;
314 /* copy data */
315 if (res->start < p->start)
316 res->start = p->start;
317 if (res->end > p->end)
318 res->end = p->end;
319 return 0;
320}
321
322/*
323 * This function calls callback against all memory range of "System RAM"
324 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
325 * Now, this function is only for "System RAM".
326 */
327int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
328 void *arg, int (*func)(unsigned long, unsigned long, void *))
329{
330 struct resource res;
331 unsigned long pfn, end_pfn;
332 u64 orig_end;
333 int ret = -1;
334
335 res.start = (u64) start_pfn << PAGE_SHIFT;
336 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
337 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
338 orig_end = res.end;
339 while ((res.start < res.end) &&
340 (find_next_system_ram(&res, "System RAM") >= 0)) {
341 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
342 end_pfn = (res.end + 1) >> PAGE_SHIFT;
343 if (end_pfn > pfn)
344 ret = (*func)(pfn, end_pfn - pfn, arg);
345 if (ret)
346 break;
347 res.start = res.end + 1;
348 res.end = orig_end;
349 }
350 return ret;
351}
352
353#endif
354
355static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
356{
357 return 1;
358}
359/*
360 * This generic page_is_ram() returns true if specified address is
361 * registered as "System RAM" in iomem_resource list.
362 */
363int __weak page_is_ram(unsigned long pfn)
364{
365 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
366}
367
368void __weak arch_remove_reservations(struct resource *avail)
369{
370}
371
372static resource_size_t simple_align_resource(void *data,
373 const struct resource *avail,
374 resource_size_t size,
375 resource_size_t align)
376{
377 return avail->start;
378}
379
380static void resource_clip(struct resource *res, resource_size_t min,
381 resource_size_t max)
382{
383 if (res->start < min)
384 res->start = min;
385 if (res->end > max)
386 res->end = max;
387}
388
389static bool resource_contains(struct resource *res1, struct resource *res2)
390{
391 return res1->start <= res2->start && res1->end >= res2->end;
392}
393
394/*
395 * Find empty slot in the resource tree with the given range and
396 * alignment constraints
397 */
398static int __find_resource(struct resource *root, struct resource *old,
399 struct resource *new,
400 resource_size_t size,
401 struct resource_constraint *constraint)
402{
403 struct resource *this = root->child;
404 struct resource tmp = *new, avail, alloc;
405
406 tmp.flags = new->flags;
407 tmp.start = root->start;
408 /*
409 * Skip past an allocated resource that starts at 0, since the assignment
410 * of this->start - 1 to tmp->end below would cause an underflow.
411 */
412 if (this && this->start == root->start) {
413 tmp.start = (this == old) ? old->start : this->end + 1;
414 this = this->sibling;
415 }
416 for(;;) {
417 if (this)
418 tmp.end = (this == old) ? this->end : this->start - 1;
419 else
420 tmp.end = root->end;
421
422 if (tmp.end < tmp.start)
423 goto next;
424
425 resource_clip(&tmp, constraint->min, constraint->max);
426 arch_remove_reservations(&tmp);
427
428 /* Check for overflow after ALIGN() */
429 avail = *new;
430 avail.start = ALIGN(tmp.start, constraint->align);
431 avail.end = tmp.end;
432 if (avail.start >= tmp.start) {
433 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
434 size, constraint->align);
435 alloc.end = alloc.start + size - 1;
436 if (resource_contains(&avail, &alloc)) {
437 new->start = alloc.start;
438 new->end = alloc.end;
439 return 0;
440 }
441 }
442
443next: if (!this || this->end == root->end)
444 break;
445
446 if (this != old)
447 tmp.start = this->end + 1;
448 this = this->sibling;
449 }
450 return -EBUSY;
451}
452
453/*
454 * Find empty slot in the resource tree given range and alignment.
455 */
456static int find_resource(struct resource *root, struct resource *new,
457 resource_size_t size,
458 struct resource_constraint *constraint)
459{
460 return __find_resource(root, NULL, new, size, constraint);
461}
462
463/**
464 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
465 * The resource will be relocated if the new size cannot be reallocated in the
466 * current location.
467 *
468 * @root: root resource descriptor
469 * @old: resource descriptor desired by caller
470 * @newsize: new size of the resource descriptor
471 * @constraint: the size and alignment constraints to be met.
472 */
473int reallocate_resource(struct resource *root, struct resource *old,
474 resource_size_t newsize,
475 struct resource_constraint *constraint)
476{
477 int err=0;
478 struct resource new = *old;
479 struct resource *conflict;
480
481 write_lock(&resource_lock);
482
483 if ((err = __find_resource(root, old, &new, newsize, constraint)))
484 goto out;
485
486 if (resource_contains(&new, old)) {
487 old->start = new.start;
488 old->end = new.end;
489 goto out;
490 }
491
492 if (old->child) {
493 err = -EBUSY;
494 goto out;
495 }
496
497 if (resource_contains(old, &new)) {
498 old->start = new.start;
499 old->end = new.end;
500 } else {
501 __release_resource(old);
502 *old = new;
503 conflict = __request_resource(root, old);
504 BUG_ON(conflict);
505 }
506out:
507 write_unlock(&resource_lock);
508 return err;
509}
510
511
512/**
513 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
514 * The resource will be reallocated with a new size if it was already allocated
515 * @root: root resource descriptor
516 * @new: resource descriptor desired by caller
517 * @size: requested resource region size
518 * @min: minimum boundary to allocate
519 * @max: maximum boundary to allocate
520 * @align: alignment requested, in bytes
521 * @alignf: alignment function, optional, called if not NULL
522 * @alignf_data: arbitrary data to pass to the @alignf function
523 */
524int allocate_resource(struct resource *root, struct resource *new,
525 resource_size_t size, resource_size_t min,
526 resource_size_t max, resource_size_t align,
527 resource_size_t (*alignf)(void *,
528 const struct resource *,
529 resource_size_t,
530 resource_size_t),
531 void *alignf_data)
532{
533 int err;
534 struct resource_constraint constraint;
535
536 if (!alignf)
537 alignf = simple_align_resource;
538
539 constraint.min = min;
540 constraint.max = max;
541 constraint.align = align;
542 constraint.alignf = alignf;
543 constraint.alignf_data = alignf_data;
544
545 if ( new->parent ) {
546 /* resource is already allocated, try reallocating with
547 the new constraints */
548 return reallocate_resource(root, new, size, &constraint);
549 }
550
551 write_lock(&resource_lock);
552 err = find_resource(root, new, size, &constraint);
553 if (err >= 0 && __request_resource(root, new))
554 err = -EBUSY;
555 write_unlock(&resource_lock);
556 return err;
557}
558
559EXPORT_SYMBOL(allocate_resource);
560
561/**
562 * lookup_resource - find an existing resource by a resource start address
563 * @root: root resource descriptor
564 * @start: resource start address
565 *
566 * Returns a pointer to the resource if found, NULL otherwise
567 */
568struct resource *lookup_resource(struct resource *root, resource_size_t start)
569{
570 struct resource *res;
571
572 read_lock(&resource_lock);
573 for (res = root->child; res; res = res->sibling) {
574 if (res->start == start)
575 break;
576 }
577 read_unlock(&resource_lock);
578
579 return res;
580}
581
582/*
583 * Insert a resource into the resource tree. If successful, return NULL,
584 * otherwise return the conflicting resource (compare to __request_resource())
585 */
586static struct resource * __insert_resource(struct resource *parent, struct resource *new)
587{
588 struct resource *first, *next;
589
590 for (;; parent = first) {
591 first = __request_resource(parent, new);
592 if (!first)
593 return first;
594
595 if (first == parent)
596 return first;
597 if (WARN_ON(first == new)) /* duplicated insertion */
598 return first;
599
600 if ((first->start > new->start) || (first->end < new->end))
601 break;
602 if ((first->start == new->start) && (first->end == new->end))
603 break;
604 }
605
606 for (next = first; ; next = next->sibling) {
607 /* Partial overlap? Bad, and unfixable */
608 if (next->start < new->start || next->end > new->end)
609 return next;
610 if (!next->sibling)
611 break;
612 if (next->sibling->start > new->end)
613 break;
614 }
615
616 new->parent = parent;
617 new->sibling = next->sibling;
618 new->child = first;
619
620 next->sibling = NULL;
621 for (next = first; next; next = next->sibling)
622 next->parent = new;
623
624 if (parent->child == first) {
625 parent->child = new;
626 } else {
627 next = parent->child;
628 while (next->sibling != first)
629 next = next->sibling;
630 next->sibling = new;
631 }
632 return NULL;
633}
634
635/**
636 * insert_resource_conflict - Inserts resource in the resource tree
637 * @parent: parent of the new resource
638 * @new: new resource to insert
639 *
640 * Returns 0 on success, conflict resource if the resource can't be inserted.
641 *
642 * This function is equivalent to request_resource_conflict when no conflict
643 * happens. If a conflict happens, and the conflicting resources
644 * entirely fit within the range of the new resource, then the new
645 * resource is inserted and the conflicting resources become children of
646 * the new resource.
647 */
648struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
649{
650 struct resource *conflict;
651
652 write_lock(&resource_lock);
653 conflict = __insert_resource(parent, new);
654 write_unlock(&resource_lock);
655 return conflict;
656}
657
658/**
659 * insert_resource - Inserts a resource in the resource tree
660 * @parent: parent of the new resource
661 * @new: new resource to insert
662 *
663 * Returns 0 on success, -EBUSY if the resource can't be inserted.
664 */
665int insert_resource(struct resource *parent, struct resource *new)
666{
667 struct resource *conflict;
668
669 conflict = insert_resource_conflict(parent, new);
670 return conflict ? -EBUSY : 0;
671}
672
673/**
674 * insert_resource_expand_to_fit - Insert a resource into the resource tree
675 * @root: root resource descriptor
676 * @new: new resource to insert
677 *
678 * Insert a resource into the resource tree, possibly expanding it in order
679 * to make it encompass any conflicting resources.
680 */
681void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
682{
683 if (new->parent)
684 return;
685
686 write_lock(&resource_lock);
687 for (;;) {
688 struct resource *conflict;
689
690 conflict = __insert_resource(root, new);
691 if (!conflict)
692 break;
693 if (conflict == root)
694 break;
695
696 /* Ok, expand resource to cover the conflict, then try again .. */
697 if (conflict->start < new->start)
698 new->start = conflict->start;
699 if (conflict->end > new->end)
700 new->end = conflict->end;
701
702 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
703 }
704 write_unlock(&resource_lock);
705}
706
707/**
708 * adjust_resource - modify a resource's start and size
709 * @res: resource to modify
710 * @start: new start value
711 * @size: new size
712 *
713 * Given an existing resource, change its start and size to match the
714 * arguments. Returns 0 on success, -EBUSY if it can't fit.
715 * Existing children of the resource are assumed to be immutable.
716 */
717int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
718{
719 struct resource *tmp, *parent = res->parent;
720 resource_size_t end = start + size - 1;
721 int result = -EBUSY;
722
723 write_lock(&resource_lock);
724
725 if ((start < parent->start) || (end > parent->end))
726 goto out;
727
728 for (tmp = res->child; tmp; tmp = tmp->sibling) {
729 if ((tmp->start < start) || (tmp->end > end))
730 goto out;
731 }
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
744 res->start = start;
745 res->end = end;
746 result = 0;
747
748 out:
749 write_unlock(&resource_lock);
750 return result;
751}
752EXPORT_SYMBOL(adjust_resource);
753
754static void __init __reserve_region_with_split(struct resource *root,
755 resource_size_t start, resource_size_t end,
756 const char *name)
757{
758 struct resource *parent = root;
759 struct resource *conflict;
760 struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC);
761
762 if (!res)
763 return;
764
765 res->name = name;
766 res->start = start;
767 res->end = end;
768 res->flags = IORESOURCE_BUSY;
769
770 conflict = __request_resource(parent, res);
771 if (!conflict)
772 return;
773
774 /* failed, split and try again */
775 kfree(res);
776
777 /* conflict covered whole area */
778 if (conflict->start <= start && conflict->end >= end)
779 return;
780
781 if (conflict->start > start)
782 __reserve_region_with_split(root, start, conflict->start-1, name);
783 if (conflict->end < end)
784 __reserve_region_with_split(root, conflict->end+1, end, name);
785}
786
787void __init reserve_region_with_split(struct resource *root,
788 resource_size_t start, resource_size_t end,
789 const char *name)
790{
791 write_lock(&resource_lock);
792 __reserve_region_with_split(root, start, end, name);
793 write_unlock(&resource_lock);
794}
795
796/**
797 * resource_alignment - calculate resource's alignment
798 * @res: resource pointer
799 *
800 * Returns alignment on success, 0 (invalid alignment) on failure.
801 */
802resource_size_t resource_alignment(struct resource *res)
803{
804 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
805 case IORESOURCE_SIZEALIGN:
806 return resource_size(res);
807 case IORESOURCE_STARTALIGN:
808 return res->start;
809 default:
810 return 0;
811 }
812}
813
814/*
815 * This is compatibility stuff for IO resources.
816 *
817 * Note how this, unlike the above, knows about
818 * the IO flag meanings (busy etc).
819 *
820 * request_region creates a new busy region.
821 *
822 * check_region returns non-zero if the area is already busy.
823 *
824 * release_region releases a matching busy region.
825 */
826
827static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
828
829/**
830 * __request_region - create a new busy resource region
831 * @parent: parent resource descriptor
832 * @start: resource start address
833 * @n: resource region size
834 * @name: reserving caller's ID string
835 * @flags: IO resource flags
836 */
837struct resource * __request_region(struct resource *parent,
838 resource_size_t start, resource_size_t n,
839 const char *name, int flags)
840{
841 DECLARE_WAITQUEUE(wait, current);
842 struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
843
844 if (!res)
845 return NULL;
846
847 res->name = name;
848 res->start = start;
849 res->end = start + n - 1;
850 res->flags = IORESOURCE_BUSY;
851 res->flags |= flags;
852
853 write_lock(&resource_lock);
854
855 for (;;) {
856 struct resource *conflict;
857
858 conflict = __request_resource(parent, res);
859 if (!conflict)
860 break;
861 if (conflict != parent) {
862 parent = conflict;
863 if (!(conflict->flags & IORESOURCE_BUSY))
864 continue;
865 }
866 if (conflict->flags & flags & IORESOURCE_MUXED) {
867 add_wait_queue(&muxed_resource_wait, &wait);
868 write_unlock(&resource_lock);
869 set_current_state(TASK_UNINTERRUPTIBLE);
870 schedule();
871 remove_wait_queue(&muxed_resource_wait, &wait);
872 write_lock(&resource_lock);
873 continue;
874 }
875 /* Uhhuh, that didn't work out.. */
876 kfree(res);
877 res = NULL;
878 break;
879 }
880 write_unlock(&resource_lock);
881 return res;
882}
883EXPORT_SYMBOL(__request_region);
884
885/**
886 * __check_region - check if a resource region is busy or free
887 * @parent: parent resource descriptor
888 * @start: resource start address
889 * @n: resource region size
890 *
891 * Returns 0 if the region is free at the moment it is checked,
892 * returns %-EBUSY if the region is busy.
893 *
894 * NOTE:
895 * This function is deprecated because its use is racy.
896 * Even if it returns 0, a subsequent call to request_region()
897 * may fail because another driver etc. just allocated the region.
898 * Do NOT use it. It will be removed from the kernel.
899 */
900int __check_region(struct resource *parent, resource_size_t start,
901 resource_size_t n)
902{
903 struct resource * res;
904
905 res = __request_region(parent, start, n, "check-region", 0);
906 if (!res)
907 return -EBUSY;
908
909 release_resource(res);
910 kfree(res);
911 return 0;
912}
913EXPORT_SYMBOL(__check_region);
914
915/**
916 * __release_region - release a previously reserved resource region
917 * @parent: parent resource descriptor
918 * @start: resource start address
919 * @n: resource region size
920 *
921 * The described resource region must match a currently busy region.
922 */
923void __release_region(struct resource *parent, resource_size_t start,
924 resource_size_t n)
925{
926 struct resource **p;
927 resource_size_t end;
928
929 p = &parent->child;
930 end = start + n - 1;
931
932 write_lock(&resource_lock);
933
934 for (;;) {
935 struct resource *res = *p;
936
937 if (!res)
938 break;
939 if (res->start <= start && res->end >= end) {
940 if (!(res->flags & IORESOURCE_BUSY)) {
941 p = &res->child;
942 continue;
943 }
944 if (res->start != start || res->end != end)
945 break;
946 *p = res->sibling;
947 write_unlock(&resource_lock);
948 if (res->flags & IORESOURCE_MUXED)
949 wake_up(&muxed_resource_wait);
950 kfree(res);
951 return;
952 }
953 p = &res->sibling;
954 }
955
956 write_unlock(&resource_lock);
957
958 printk(KERN_WARNING "Trying to free nonexistent resource "
959 "<%016llx-%016llx>\n", (unsigned long long)start,
960 (unsigned long long)end);
961}
962EXPORT_SYMBOL(__release_region);
963
964/*
965 * Managed region resource
966 */
967struct region_devres {
968 struct resource *parent;
969 resource_size_t start;
970 resource_size_t n;
971};
972
973static void devm_region_release(struct device *dev, void *res)
974{
975 struct region_devres *this = res;
976
977 __release_region(this->parent, this->start, this->n);
978}
979
980static int devm_region_match(struct device *dev, void *res, void *match_data)
981{
982 struct region_devres *this = res, *match = match_data;
983
984 return this->parent == match->parent &&
985 this->start == match->start && this->n == match->n;
986}
987
988struct resource * __devm_request_region(struct device *dev,
989 struct resource *parent, resource_size_t start,
990 resource_size_t n, const char *name)
991{
992 struct region_devres *dr = NULL;
993 struct resource *res;
994
995 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
996 GFP_KERNEL);
997 if (!dr)
998 return NULL;
999
1000 dr->parent = parent;
1001 dr->start = start;
1002 dr->n = n;
1003
1004 res = __request_region(parent, start, n, name, 0);
1005 if (res)
1006 devres_add(dev, dr);
1007 else
1008 devres_free(dr);
1009
1010 return res;
1011}
1012EXPORT_SYMBOL(__devm_request_region);
1013
1014void __devm_release_region(struct device *dev, struct resource *parent,
1015 resource_size_t start, resource_size_t n)
1016{
1017 struct region_devres match_data = { parent, start, n };
1018
1019 __release_region(parent, start, n);
1020 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1021 &match_data));
1022}
1023EXPORT_SYMBOL(__devm_release_region);
1024
1025/*
1026 * Called from init/main.c to reserve IO ports.
1027 */
1028#define MAXRESERVE 4
1029static int __init reserve_setup(char *str)
1030{
1031 static int reserved;
1032 static struct resource reserve[MAXRESERVE];
1033
1034 for (;;) {
1035 unsigned int io_start, io_num;
1036 int x = reserved;
1037
1038 if (get_option (&str, &io_start) != 2)
1039 break;
1040 if (get_option (&str, &io_num) == 0)
1041 break;
1042 if (x < MAXRESERVE) {
1043 struct resource *res = reserve + x;
1044 res->name = "reserved";
1045 res->start = io_start;
1046 res->end = io_start + io_num - 1;
1047 res->flags = IORESOURCE_BUSY;
1048 res->child = NULL;
1049 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
1050 reserved = x+1;
1051 }
1052 }
1053 return 1;
1054}
1055
1056__setup("reserve=", reserve_setup);
1057
1058/*
1059 * Check if the requested addr and size spans more than any slot in the
1060 * iomem resource tree.
1061 */
1062int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1063{
1064 struct resource *p = &iomem_resource;
1065 int err = 0;
1066 loff_t l;
1067
1068 read_lock(&resource_lock);
1069 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1070 /*
1071 * We can probably skip the resources without
1072 * IORESOURCE_IO attribute?
1073 */
1074 if (p->start >= addr + size)
1075 continue;
1076 if (p->end < addr)
1077 continue;
1078 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1079 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1080 continue;
1081 /*
1082 * if a resource is "BUSY", it's not a hardware resource
1083 * but a driver mapping of such a resource; we don't want
1084 * to warn for those; some drivers legitimately map only
1085 * partial hardware resources. (example: vesafb)
1086 */
1087 if (p->flags & IORESOURCE_BUSY)
1088 continue;
1089
1090 printk(KERN_WARNING "resource map sanity check conflict: "
1091 "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
1092 (unsigned long long)addr,
1093 (unsigned long long)(addr + size - 1),
1094 (unsigned long long)p->start,
1095 (unsigned long long)p->end,
1096 p->name);
1097 err = -1;
1098 break;
1099 }
1100 read_unlock(&resource_lock);
1101
1102 return err;
1103}
1104
1105#ifdef CONFIG_STRICT_DEVMEM
1106static int strict_iomem_checks = 1;
1107#else
1108static int strict_iomem_checks;
1109#endif
1110
1111/*
1112 * check if an address is reserved in the iomem resource tree
1113 * returns 1 if reserved, 0 if not reserved.
1114 */
1115int iomem_is_exclusive(u64 addr)
1116{
1117 struct resource *p = &iomem_resource;
1118 int err = 0;
1119 loff_t l;
1120 int size = PAGE_SIZE;
1121
1122 if (!strict_iomem_checks)
1123 return 0;
1124
1125 addr = addr & PAGE_MASK;
1126
1127 read_lock(&resource_lock);
1128 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1129 /*
1130 * We can probably skip the resources without
1131 * IORESOURCE_IO attribute?
1132 */
1133 if (p->start >= addr + size)
1134 break;
1135 if (p->end < addr)
1136 continue;
1137 if (p->flags & IORESOURCE_BUSY &&
1138 p->flags & IORESOURCE_EXCLUSIVE) {
1139 err = 1;
1140 break;
1141 }
1142 }
1143 read_unlock(&resource_lock);
1144
1145 return err;
1146}
1147
1148static int __init strict_iomem(char *str)
1149{
1150 if (strstr(str, "relaxed"))
1151 strict_iomem_checks = 0;
1152 if (strstr(str, "strict"))
1153 strict_iomem_checks = 1;
1154 return 1;
1155}
1156
1157__setup("iomem=", strict_iomem);