projects/linux·blob v4.16 · refs

1654 lines · 40.2 KiB

1/*
2 * linux/kernel/resource.c
3 *
4 * Copyright (C) 1999 Linus Torvalds
5 * Copyright (C) 1999 Martin Mares <[email protected]>
6 *
7 * Arbitrary resource management.
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/export.h>
13#include <linux/errno.h>
14#include <linux/ioport.h>
15#include <linux/init.h>
16#include <linux/slab.h>
17#include <linux/spinlock.h>
18#include <linux/fs.h>
19#include <linux/proc_fs.h>
20#include <linux/sched.h>
21#include <linux/seq_file.h>
22#include <linux/device.h>
23#include <linux/pfn.h>
24#include <linux/mm.h>
25#include <linux/resource_ext.h>
26#include <asm/io.h>
27
28
29struct resource ioport_resource = {
30 .name = "PCI IO",
31 .start = 0,
32 .end = IO_SPACE_LIMIT,
33 .flags = IORESOURCE_IO,
34};
35EXPORT_SYMBOL(ioport_resource);
36
37struct resource iomem_resource = {
38 .name = "PCI mem",
39 .start = 0,
40 .end = -1,
41 .flags = IORESOURCE_MEM,
42};
43EXPORT_SYMBOL(iomem_resource);
44
45/* constraints to be met while allocating resources */
46struct resource_constraint {
47 resource_size_t min, max, align;
48 resource_size_t (*alignf)(void *, const struct resource *,
49 resource_size_t, resource_size_t);
50 void *alignf_data;
51};
52
53static DEFINE_RWLOCK(resource_lock);
54
55/*
56 * For memory hotplug, there is no way to free resource entries allocated
57 * by boot mem after the system is up. So for reusing the resource entry
58 * we need to remember the resource.
59 */
60static struct resource *bootmem_resource_free;
61static DEFINE_SPINLOCK(bootmem_resource_lock);
62
63static struct resource *next_resource(struct resource *p, bool sibling_only)
64{
65 /* Caller wants to traverse through siblings only */
66 if (sibling_only)
67 return p->sibling;
68
69 if (p->child)
70 return p->child;
71 while (!p->sibling && p->parent)
72 p = p->parent;
73 return p->sibling;
74}
75
76static void *r_next(struct seq_file *m, void *v, loff_t *pos)
77{
78 struct resource *p = v;
79 (*pos)++;
80 return (void *)next_resource(p, false);
81}
82
83#ifdef CONFIG_PROC_FS
84
85enum { MAX_IORES_LEVEL = 5 };
86
87static void *r_start(struct seq_file *m, loff_t *pos)
88 __acquires(resource_lock)
89{
90 struct resource *p = m->private;
91 loff_t l = 0;
92 read_lock(&resource_lock);
93 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
94 ;
95 return p;
96}
97
98static void r_stop(struct seq_file *m, void *v)
99 __releases(resource_lock)
100{
101 read_unlock(&resource_lock);
102}
103
104static int r_show(struct seq_file *m, void *v)
105{
106 struct resource *root = m->private;
107 struct resource *r = v, *p;
108 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 (resource_contains(&avail, &alloc)) {
655 new->start = alloc.start;
656 new->end = alloc.end;
657 return 0;
658 }
659 }
660
661next: if (!this || this->end == root->end)
662 break;
663
664 if (this != old)
665 tmp.start = this->end + 1;
666 this = this->sibling;
667 }
668 return -EBUSY;
669}
670
671/*
672 * Find empty slot in the resource tree given range and alignment.
673 */
674static int find_resource(struct resource *root, struct resource *new,
675 resource_size_t size,
676 struct resource_constraint *constraint)
677{
678 return __find_resource(root, NULL, new, size, constraint);
679}
680
681/**
682 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
683 * The resource will be relocated if the new size cannot be reallocated in the
684 * current location.
685 *
686 * @root: root resource descriptor
687 * @old: resource descriptor desired by caller
688 * @newsize: new size of the resource descriptor
689 * @constraint: the size and alignment constraints to be met.
690 */
691static int reallocate_resource(struct resource *root, struct resource *old,
692 resource_size_t newsize,
693 struct resource_constraint *constraint)
694{
695 int err=0;
696 struct resource new = *old;
697 struct resource *conflict;
698
699 write_lock(&resource_lock);
700
701 if ((err = __find_resource(root, old, &new, newsize, constraint)))
702 goto out;
703
704 if (resource_contains(&new, old)) {
705 old->start = new.start;
706 old->end = new.end;
707 goto out;
708 }
709
710 if (old->child) {
711 err = -EBUSY;
712 goto out;
713 }
714
715 if (resource_contains(old, &new)) {
716 old->start = new.start;
717 old->end = new.end;
718 } else {
719 __release_resource(old, true);
720 *old = new;
721 conflict = __request_resource(root, old);
722 BUG_ON(conflict);
723 }
724out:
725 write_unlock(&resource_lock);
726 return err;
727}
728
729
730/**
731 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
732 * The resource will be reallocated with a new size if it was already allocated
733 * @root: root resource descriptor
734 * @new: resource descriptor desired by caller
735 * @size: requested resource region size
736 * @min: minimum boundary to allocate
737 * @max: maximum boundary to allocate
738 * @align: alignment requested, in bytes
739 * @alignf: alignment function, optional, called if not NULL
740 * @alignf_data: arbitrary data to pass to the @alignf function
741 */
742int allocate_resource(struct resource *root, struct resource *new,
743 resource_size_t size, resource_size_t min,
744 resource_size_t max, resource_size_t align,
745 resource_size_t (*alignf)(void *,
746 const struct resource *,
747 resource_size_t,
748 resource_size_t),
749 void *alignf_data)
750{
751 int err;
752 struct resource_constraint constraint;
753
754 if (!alignf)
755 alignf = simple_align_resource;
756
757 constraint.min = min;
758 constraint.max = max;
759 constraint.align = align;
760 constraint.alignf = alignf;
761 constraint.alignf_data = alignf_data;
762
763 if ( new->parent ) {
764 /* resource is already allocated, try reallocating with
765 the new constraints */
766 return reallocate_resource(root, new, size, &constraint);
767 }
768
769 write_lock(&resource_lock);
770 err = find_resource(root, new, size, &constraint);
771 if (err >= 0 && __request_resource(root, new))
772 err = -EBUSY;
773 write_unlock(&resource_lock);
774 return err;
775}
776
777EXPORT_SYMBOL(allocate_resource);
778
779/**
780 * lookup_resource - find an existing resource by a resource start address
781 * @root: root resource descriptor
782 * @start: resource start address
783 *
784 * Returns a pointer to the resource if found, NULL otherwise
785 */
786struct resource *lookup_resource(struct resource *root, resource_size_t start)
787{
788 struct resource *res;
789
790 read_lock(&resource_lock);
791 for (res = root->child; res; res = res->sibling) {
792 if (res->start == start)
793 break;
794 }
795 read_unlock(&resource_lock);
796
797 return res;
798}
799
800/*
801 * Insert a resource into the resource tree. If successful, return NULL,
802 * otherwise return the conflicting resource (compare to __request_resource())
803 */
804static struct resource * __insert_resource(struct resource *parent, struct resource *new)
805{
806 struct resource *first, *next;
807
808 for (;; parent = first) {
809 first = __request_resource(parent, new);
810 if (!first)
811 return first;
812
813 if (first == parent)
814 return first;
815 if (WARN_ON(first == new)) /* duplicated insertion */
816 return first;
817
818 if ((first->start > new->start) || (first->end < new->end))
819 break;
820 if ((first->start == new->start) && (first->end == new->end))
821 break;
822 }
823
824 for (next = first; ; next = next->sibling) {
825 /* Partial overlap? Bad, and unfixable */
826 if (next->start < new->start || next->end > new->end)
827 return next;
828 if (!next->sibling)
829 break;
830 if (next->sibling->start > new->end)
831 break;
832 }
833
834 new->parent = parent;
835 new->sibling = next->sibling;
836 new->child = first;
837
838 next->sibling = NULL;
839 for (next = first; next; next = next->sibling)
840 next->parent = new;
841
842 if (parent->child == first) {
843 parent->child = new;
844 } else {
845 next = parent->child;
846 while (next->sibling != first)
847 next = next->sibling;
848 next->sibling = new;
849 }
850 return NULL;
851}
852
853/**
854 * insert_resource_conflict - Inserts resource in the resource tree
855 * @parent: parent of the new resource
856 * @new: new resource to insert
857 *
858 * Returns 0 on success, conflict resource if the resource can't be inserted.
859 *
860 * This function is equivalent to request_resource_conflict when no conflict
861 * happens. If a conflict happens, and the conflicting resources
862 * entirely fit within the range of the new resource, then the new
863 * resource is inserted and the conflicting resources become children of
864 * the new resource.
865 *
866 * This function is intended for producers of resources, such as FW modules
867 * and bus drivers.
868 */
869struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
870{
871 struct resource *conflict;
872
873 write_lock(&resource_lock);
874 conflict = __insert_resource(parent, new);
875 write_unlock(&resource_lock);
876 return conflict;
877}
878
879/**
880 * insert_resource - Inserts a resource in the resource tree
881 * @parent: parent of the new resource
882 * @new: new resource to insert
883 *
884 * Returns 0 on success, -EBUSY if the resource can't be inserted.
885 *
886 * This function is intended for producers of resources, such as FW modules
887 * and bus drivers.
888 */
889int insert_resource(struct resource *parent, struct resource *new)
890{
891 struct resource *conflict;
892
893 conflict = insert_resource_conflict(parent, new);
894 return conflict ? -EBUSY : 0;
895}
896EXPORT_SYMBOL_GPL(insert_resource);
897
898/**
899 * insert_resource_expand_to_fit - Insert a resource into the resource tree
900 * @root: root resource descriptor
901 * @new: new resource to insert
902 *
903 * Insert a resource into the resource tree, possibly expanding it in order
904 * to make it encompass any conflicting resources.
905 */
906void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
907{
908 if (new->parent)
909 return;
910
911 write_lock(&resource_lock);
912 for (;;) {
913 struct resource *conflict;
914
915 conflict = __insert_resource(root, new);
916 if (!conflict)
917 break;
918 if (conflict == root)
919 break;
920
921 /* Ok, expand resource to cover the conflict, then try again .. */
922 if (conflict->start < new->start)
923 new->start = conflict->start;
924 if (conflict->end > new->end)
925 new->end = conflict->end;
926
927 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
928 }
929 write_unlock(&resource_lock);
930}
931
932/**
933 * remove_resource - Remove a resource in the resource tree
934 * @old: resource to remove
935 *
936 * Returns 0 on success, -EINVAL if the resource is not valid.
937 *
938 * This function removes a resource previously inserted by insert_resource()
939 * or insert_resource_conflict(), and moves the children (if any) up to
940 * where they were before. insert_resource() and insert_resource_conflict()
941 * insert a new resource, and move any conflicting resources down to the
942 * children of the new resource.
943 *
944 * insert_resource(), insert_resource_conflict() and remove_resource() are
945 * intended for producers of resources, such as FW modules and bus drivers.
946 */
947int remove_resource(struct resource *old)
948{
949 int retval;
950
951 write_lock(&resource_lock);
952 retval = __release_resource(old, false);
953 write_unlock(&resource_lock);
954 return retval;
955}
956EXPORT_SYMBOL_GPL(remove_resource);
957
958static int __adjust_resource(struct resource *res, resource_size_t start,
959 resource_size_t size)
960{
961 struct resource *tmp, *parent = res->parent;
962 resource_size_t end = start + size - 1;
963 int result = -EBUSY;
964
965 if (!parent)
966 goto skip;
967
968 if ((start < parent->start) || (end > parent->end))
969 goto out;
970
971 if (res->sibling && (res->sibling->start <= end))
972 goto out;
973
974 tmp = parent->child;
975 if (tmp != res) {
976 while (tmp->sibling != res)
977 tmp = tmp->sibling;
978 if (start <= tmp->end)
979 goto out;
980 }
981
982skip:
983 for (tmp = res->child; tmp; tmp = tmp->sibling)
984 if ((tmp->start < start) || (tmp->end > end))
985 goto out;
986
987 res->start = start;
988 res->end = end;
989 result = 0;
990
991 out:
992 return result;
993}
994
995/**
996 * adjust_resource - modify a resource's start and size
997 * @res: resource to modify
998 * @start: new start value
999 * @size: new size
1000 *
1001 * Given an existing resource, change its start and size to match the
1002 * arguments. Returns 0 on success, -EBUSY if it can't fit.
1003 * Existing children of the resource are assumed to be immutable.
1004 */
1005int adjust_resource(struct resource *res, resource_size_t start,
1006 resource_size_t size)
1007{
1008 int result;
1009
1010 write_lock(&resource_lock);
1011 result = __adjust_resource(res, start, size);
1012 write_unlock(&resource_lock);
1013 return result;
1014}
1015EXPORT_SYMBOL(adjust_resource);
1016
1017static void __init __reserve_region_with_split(struct resource *root,
1018 resource_size_t start, resource_size_t end,
1019 const char *name)
1020{
1021 struct resource *parent = root;
1022 struct resource *conflict;
1023 struct resource *res = alloc_resource(GFP_ATOMIC);
1024 struct resource *next_res = NULL;
1025 int type = resource_type(root);
1026
1027 if (!res)
1028 return;
1029
1030 res->name = name;
1031 res->start = start;
1032 res->end = end;
1033 res->flags = type | IORESOURCE_BUSY;
1034 res->desc = IORES_DESC_NONE;
1035
1036 while (1) {
1037
1038 conflict = __request_resource(parent, res);
1039 if (!conflict) {
1040 if (!next_res)
1041 break;
1042 res = next_res;
1043 next_res = NULL;
1044 continue;
1045 }
1046
1047 /* conflict covered whole area */
1048 if (conflict->start <= res->start &&
1049 conflict->end >= res->end) {
1050 free_resource(res);
1051 WARN_ON(next_res);
1052 break;
1053 }
1054
1055 /* failed, split and try again */
1056 if (conflict->start > res->start) {
1057 end = res->end;
1058 res->end = conflict->start - 1;
1059 if (conflict->end < end) {
1060 next_res = alloc_resource(GFP_ATOMIC);
1061 if (!next_res) {
1062 free_resource(res);
1063 break;
1064 }
1065 next_res->name = name;
1066 next_res->start = conflict->end + 1;
1067 next_res->end = end;
1068 next_res->flags = type | IORESOURCE_BUSY;
1069 next_res->desc = IORES_DESC_NONE;
1070 }
1071 } else {
1072 res->start = conflict->end + 1;
1073 }
1074 }
1075
1076}
1077
1078void __init reserve_region_with_split(struct resource *root,
1079 resource_size_t start, resource_size_t end,
1080 const char *name)
1081{
1082 int abort = 0;
1083
1084 write_lock(&resource_lock);
1085 if (root->start > start || root->end < end) {
1086 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1087 (unsigned long long)start, (unsigned long long)end,
1088 root);
1089 if (start > root->end || end < root->start)
1090 abort = 1;
1091 else {
1092 if (end > root->end)
1093 end = root->end;
1094 if (start < root->start)
1095 start = root->start;
1096 pr_err("fixing request to [0x%llx-0x%llx]\n",
1097 (unsigned long long)start,
1098 (unsigned long long)end);
1099 }
1100 dump_stack();
1101 }
1102 if (!abort)
1103 __reserve_region_with_split(root, start, end, name);
1104 write_unlock(&resource_lock);
1105}
1106
1107/**
1108 * resource_alignment - calculate resource's alignment
1109 * @res: resource pointer
1110 *
1111 * Returns alignment on success, 0 (invalid alignment) on failure.
1112 */
1113resource_size_t resource_alignment(struct resource *res)
1114{
1115 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1116 case IORESOURCE_SIZEALIGN:
1117 return resource_size(res);
1118 case IORESOURCE_STARTALIGN:
1119 return res->start;
1120 default:
1121 return 0;
1122 }
1123}
1124
1125/*
1126 * This is compatibility stuff for IO resources.
1127 *
1128 * Note how this, unlike the above, knows about
1129 * the IO flag meanings (busy etc).
1130 *
1131 * request_region creates a new busy region.
1132 *
1133 * release_region releases a matching busy region.
1134 */
1135
1136static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1137
1138/**
1139 * __request_region - create a new busy resource region
1140 * @parent: parent resource descriptor
1141 * @start: resource start address
1142 * @n: resource region size
1143 * @name: reserving caller's ID string
1144 * @flags: IO resource flags
1145 */
1146struct resource * __request_region(struct resource *parent,
1147 resource_size_t start, resource_size_t n,
1148 const char *name, int flags)
1149{
1150 DECLARE_WAITQUEUE(wait, current);
1151 struct resource *res = alloc_resource(GFP_KERNEL);
1152
1153 if (!res)
1154 return NULL;
1155
1156 res->name = name;
1157 res->start = start;
1158 res->end = start + n - 1;
1159
1160 write_lock(&resource_lock);
1161
1162 for (;;) {
1163 struct resource *conflict;
1164
1165 res->flags = resource_type(parent) | resource_ext_type(parent);
1166 res->flags |= IORESOURCE_BUSY | flags;
1167 res->desc = parent->desc;
1168
1169 conflict = __request_resource(parent, res);
1170 if (!conflict)
1171 break;
1172 if (conflict != parent) {
1173 if (!(conflict->flags & IORESOURCE_BUSY)) {
1174 parent = conflict;
1175 continue;
1176 }
1177 }
1178 if (conflict->flags & flags & IORESOURCE_MUXED) {
1179 add_wait_queue(&muxed_resource_wait, &wait);
1180 write_unlock(&resource_lock);
1181 set_current_state(TASK_UNINTERRUPTIBLE);
1182 schedule();
1183 remove_wait_queue(&muxed_resource_wait, &wait);
1184 write_lock(&resource_lock);
1185 continue;
1186 }
1187 /* Uhhuh, that didn't work out.. */
1188 free_resource(res);
1189 res = NULL;
1190 break;
1191 }
1192 write_unlock(&resource_lock);
1193 return res;
1194}
1195EXPORT_SYMBOL(__request_region);
1196
1197/**
1198 * __release_region - release a previously reserved resource region
1199 * @parent: parent resource descriptor
1200 * @start: resource start address
1201 * @n: resource region size
1202 *
1203 * The described resource region must match a currently busy region.
1204 */
1205void __release_region(struct resource *parent, resource_size_t start,
1206 resource_size_t n)
1207{
1208 struct resource **p;
1209 resource_size_t end;
1210
1211 p = &parent->child;
1212 end = start + n - 1;
1213
1214 write_lock(&resource_lock);
1215
1216 for (;;) {
1217 struct resource *res = *p;
1218
1219 if (!res)
1220 break;
1221 if (res->start <= start && res->end >= end) {
1222 if (!(res->flags & IORESOURCE_BUSY)) {
1223 p = &res->child;
1224 continue;
1225 }
1226 if (res->start != start || res->end != end)
1227 break;
1228 *p = res->sibling;
1229 write_unlock(&resource_lock);
1230 if (res->flags & IORESOURCE_MUXED)
1231 wake_up(&muxed_resource_wait);
1232 free_resource(res);
1233 return;
1234 }
1235 p = &res->sibling;
1236 }
1237
1238 write_unlock(&resource_lock);
1239
1240 printk(KERN_WARNING "Trying to free nonexistent resource "
1241 "<%016llx-%016llx>\n", (unsigned long long)start,
1242 (unsigned long long)end);
1243}
1244EXPORT_SYMBOL(__release_region);
1245
1246#ifdef CONFIG_MEMORY_HOTREMOVE
1247/**
1248 * release_mem_region_adjustable - release a previously reserved memory region
1249 * @parent: parent resource descriptor
1250 * @start: resource start address
1251 * @size: resource region size
1252 *
1253 * This interface is intended for memory hot-delete. The requested region
1254 * is released from a currently busy memory resource. The requested region
1255 * must either match exactly or fit into a single busy resource entry. In
1256 * the latter case, the remaining resource is adjusted accordingly.
1257 * Existing children of the busy memory resource must be immutable in the
1258 * request.
1259 *
1260 * Note:
1261 * - Additional release conditions, such as overlapping region, can be
1262 * supported after they are confirmed as valid cases.
1263 * - When a busy memory resource gets split into two entries, the code
1264 * assumes that all children remain in the lower address entry for
1265 * simplicity. Enhance this logic when necessary.
1266 */
1267int release_mem_region_adjustable(struct resource *parent,
1268 resource_size_t start, resource_size_t size)
1269{
1270 struct resource **p;
1271 struct resource *res;
1272 struct resource *new_res;
1273 resource_size_t end;
1274 int ret = -EINVAL;
1275
1276 end = start + size - 1;
1277 if ((start < parent->start) || (end > parent->end))
1278 return ret;
1279
1280 /* The alloc_resource() result gets checked later */
1281 new_res = alloc_resource(GFP_KERNEL);
1282
1283 p = &parent->child;
1284 write_lock(&resource_lock);
1285
1286 while ((res = *p)) {
1287 if (res->start >= end)
1288 break;
1289
1290 /* look for the next resource if it does not fit into */
1291 if (res->start > start || res->end < end) {
1292 p = &res->sibling;
1293 continue;
1294 }
1295
1296 if (!(res->flags & IORESOURCE_MEM))
1297 break;
1298
1299 if (!(res->flags & IORESOURCE_BUSY)) {
1300 p = &res->child;
1301 continue;
1302 }
1303
1304 /* found the target resource; let's adjust accordingly */
1305 if (res->start == start && res->end == end) {
1306 /* free the whole entry */
1307 *p = res->sibling;
1308 free_resource(res);
1309 ret = 0;
1310 } else if (res->start == start && res->end != end) {
1311 /* adjust the start */
1312 ret = __adjust_resource(res, end + 1,
1313 res->end - end);
1314 } else if (res->start != start && res->end == end) {
1315 /* adjust the end */
1316 ret = __adjust_resource(res, res->start,
1317 start - res->start);
1318 } else {
1319 /* split into two entries */
1320 if (!new_res) {
1321 ret = -ENOMEM;
1322 break;
1323 }
1324 new_res->name = res->name;
1325 new_res->start = end + 1;
1326 new_res->end = res->end;
1327 new_res->flags = res->flags;
1328 new_res->desc = res->desc;
1329 new_res->parent = res->parent;
1330 new_res->sibling = res->sibling;
1331 new_res->child = NULL;
1332
1333 ret = __adjust_resource(res, res->start,
1334 start - res->start);
1335 if (ret)
1336 break;
1337 res->sibling = new_res;
1338 new_res = NULL;
1339 }
1340
1341 break;
1342 }
1343
1344 write_unlock(&resource_lock);
1345 free_resource(new_res);
1346 return ret;
1347}
1348#endif /* CONFIG_MEMORY_HOTREMOVE */
1349
1350/*
1351 * Managed region resource
1352 */
1353static void devm_resource_release(struct device *dev, void *ptr)
1354{
1355 struct resource **r = ptr;
1356
1357 release_resource(*r);
1358}
1359
1360/**
1361 * devm_request_resource() - request and reserve an I/O or memory resource
1362 * @dev: device for which to request the resource
1363 * @root: root of the resource tree from which to request the resource
1364 * @new: descriptor of the resource to request
1365 *
1366 * This is a device-managed version of request_resource(). There is usually
1367 * no need to release resources requested by this function explicitly since
1368 * that will be taken care of when the device is unbound from its driver.
1369 * If for some reason the resource needs to be released explicitly, because
1370 * of ordering issues for example, drivers must call devm_release_resource()
1371 * rather than the regular release_resource().
1372 *
1373 * When a conflict is detected between any existing resources and the newly
1374 * requested resource, an error message will be printed.
1375 *
1376 * Returns 0 on success or a negative error code on failure.
1377 */
1378int devm_request_resource(struct device *dev, struct resource *root,
1379 struct resource *new)
1380{
1381 struct resource *conflict, **ptr;
1382
1383 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1384 if (!ptr)
1385 return -ENOMEM;
1386
1387 *ptr = new;
1388
1389 conflict = request_resource_conflict(root, new);
1390 if (conflict) {
1391 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1392 new, conflict->name, conflict);
1393 devres_free(ptr);
1394 return -EBUSY;
1395 }
1396
1397 devres_add(dev, ptr);
1398 return 0;
1399}
1400EXPORT_SYMBOL(devm_request_resource);
1401
1402static int devm_resource_match(struct device *dev, void *res, void *data)
1403{
1404 struct resource **ptr = res;
1405
1406 return *ptr == data;
1407}
1408
1409/**
1410 * devm_release_resource() - release a previously requested resource
1411 * @dev: device for which to release the resource
1412 * @new: descriptor of the resource to release
1413 *
1414 * Releases a resource previously requested using devm_request_resource().
1415 */
1416void devm_release_resource(struct device *dev, struct resource *new)
1417{
1418 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1419 new));
1420}
1421EXPORT_SYMBOL(devm_release_resource);
1422
1423struct region_devres {
1424 struct resource *parent;
1425 resource_size_t start;
1426 resource_size_t n;
1427};
1428
1429static void devm_region_release(struct device *dev, void *res)
1430{
1431 struct region_devres *this = res;
1432
1433 __release_region(this->parent, this->start, this->n);
1434}
1435
1436static int devm_region_match(struct device *dev, void *res, void *match_data)
1437{
1438 struct region_devres *this = res, *match = match_data;
1439
1440 return this->parent == match->parent &&
1441 this->start == match->start && this->n == match->n;
1442}
1443
1444struct resource * __devm_request_region(struct device *dev,
1445 struct resource *parent, resource_size_t start,
1446 resource_size_t n, const char *name)
1447{
1448 struct region_devres *dr = NULL;
1449 struct resource *res;
1450
1451 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1452 GFP_KERNEL);
1453 if (!dr)
1454 return NULL;
1455
1456 dr->parent = parent;
1457 dr->start = start;
1458 dr->n = n;
1459
1460 res = __request_region(parent, start, n, name, 0);
1461 if (res)
1462 devres_add(dev, dr);
1463 else
1464 devres_free(dr);
1465
1466 return res;
1467}
1468EXPORT_SYMBOL(__devm_request_region);
1469
1470void __devm_release_region(struct device *dev, struct resource *parent,
1471 resource_size_t start, resource_size_t n)
1472{
1473 struct region_devres match_data = { parent, start, n };
1474
1475 __release_region(parent, start, n);
1476 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1477 &match_data));
1478}
1479EXPORT_SYMBOL(__devm_release_region);
1480
1481/*
1482 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1483 */
1484#define MAXRESERVE 4
1485static int __init reserve_setup(char *str)
1486{
1487 static int reserved;
1488 static struct resource reserve[MAXRESERVE];
1489
1490 for (;;) {
1491 unsigned int io_start, io_num;
1492 int x = reserved;
1493 struct resource *parent;
1494
1495 if (get_option(&str, &io_start) != 2)
1496 break;
1497 if (get_option(&str, &io_num) == 0)
1498 break;
1499 if (x < MAXRESERVE) {
1500 struct resource *res = reserve + x;
1501
1502 /*
1503 * If the region starts below 0x10000, we assume it's
1504 * I/O port space; otherwise assume it's memory.
1505 */
1506 if (io_start < 0x10000) {
1507 res->flags = IORESOURCE_IO;
1508 parent = &ioport_resource;
1509 } else {
1510 res->flags = IORESOURCE_MEM;
1511 parent = &iomem_resource;
1512 }
1513 res->name = "reserved";
1514 res->start = io_start;
1515 res->end = io_start + io_num - 1;
1516 res->flags |= IORESOURCE_BUSY;
1517 res->desc = IORES_DESC_NONE;
1518 res->child = NULL;
1519 if (request_resource(parent, res) == 0)
1520 reserved = x+1;
1521 }
1522 }
1523 return 1;
1524}
1525__setup("reserve=", reserve_setup);
1526
1527/*
1528 * Check if the requested addr and size spans more than any slot in the
1529 * iomem resource tree.
1530 */
1531int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1532{
1533 struct resource *p = &iomem_resource;
1534 int err = 0;
1535 loff_t l;
1536
1537 read_lock(&resource_lock);
1538 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1539 /*
1540 * We can probably skip the resources without
1541 * IORESOURCE_IO attribute?
1542 */
1543 if (p->start >= addr + size)
1544 continue;
1545 if (p->end < addr)
1546 continue;
1547 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1548 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1549 continue;
1550 /*
1551 * if a resource is "BUSY", it's not a hardware resource
1552 * but a driver mapping of such a resource; we don't want
1553 * to warn for those; some drivers legitimately map only
1554 * partial hardware resources. (example: vesafb)
1555 */
1556 if (p->flags & IORESOURCE_BUSY)
1557 continue;
1558
1559 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1560 (unsigned long long)addr,
1561 (unsigned long long)(addr + size - 1),
1562 p->name, p);
1563 err = -1;
1564 break;
1565 }
1566 read_unlock(&resource_lock);
1567
1568 return err;
1569}
1570
1571#ifdef CONFIG_STRICT_DEVMEM
1572static int strict_iomem_checks = 1;
1573#else
1574static int strict_iomem_checks;
1575#endif
1576
1577/*
1578 * check if an address is reserved in the iomem resource tree
1579 * returns true if reserved, false if not reserved.
1580 */
1581bool iomem_is_exclusive(u64 addr)
1582{
1583 struct resource *p = &iomem_resource;
1584 bool err = false;
1585 loff_t l;
1586 int size = PAGE_SIZE;
1587
1588 if (!strict_iomem_checks)
1589 return false;
1590
1591 addr = addr & PAGE_MASK;
1592
1593 read_lock(&resource_lock);
1594 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1595 /*
1596 * We can probably skip the resources without
1597 * IORESOURCE_IO attribute?
1598 */
1599 if (p->start >= addr + size)
1600 break;
1601 if (p->end < addr)
1602 continue;
1603 /*
1604 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1605 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1606 * resource is busy.
1607 */
1608 if ((p->flags & IORESOURCE_BUSY) == 0)
1609 continue;
1610 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1611 || p->flags & IORESOURCE_EXCLUSIVE) {
1612 err = true;
1613 break;
1614 }
1615 }
1616 read_unlock(&resource_lock);
1617
1618 return err;
1619}
1620
1621struct resource_entry *resource_list_create_entry(struct resource *res,
1622 size_t extra_size)
1623{
1624 struct resource_entry *entry;
1625
1626 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1627 if (entry) {
1628 INIT_LIST_HEAD(&entry->node);
1629 entry->res = res ? res : &entry->__res;
1630 }
1631
1632 return entry;
1633}
1634EXPORT_SYMBOL(resource_list_create_entry);
1635
1636void resource_list_free(struct list_head *head)
1637{
1638 struct resource_entry *entry, *tmp;
1639
1640 list_for_each_entry_safe(entry, tmp, head, node)
1641 resource_list_destroy_entry(entry);
1642}
1643EXPORT_SYMBOL(resource_list_free);
1644
1645static int __init strict_iomem(char *str)
1646{
1647 if (strstr(str, "relaxed"))
1648 strict_iomem_checks = 0;
1649 if (strstr(str, "strict"))
1650 strict_iomem_checks = 1;
1651 return 1;
1652}
1653
1654__setup("iomem=", strict_iomem);