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