projects/linux·blob v5.12 · refs

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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/kernel/resource.c
4 *
5 * Copyright (C) 1999 Linus Torvalds
6 * Copyright (C) 1999 Martin Mares <[email protected]>
7 *
8 * Arbitrary resource management.
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/export.h>
14#include <linux/errno.h>
15#include <linux/ioport.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18#include <linux/spinlock.h>
19#include <linux/fs.h>
20#include <linux/proc_fs.h>
21#include <linux/pseudo_fs.h>
22#include <linux/sched.h>
23#include <linux/seq_file.h>
24#include <linux/device.h>
25#include <linux/pfn.h>
26#include <linux/mm.h>
27#include <linux/mount.h>
28#include <linux/resource_ext.h>
29#include <uapi/linux/magic.h>
30#include <asm/io.h>
31
32
33struct resource ioport_resource = {
34 .name = "PCI IO",
35 .start = 0,
36 .end = IO_SPACE_LIMIT,
37 .flags = IORESOURCE_IO,
38};
39EXPORT_SYMBOL(ioport_resource);
40
41struct resource iomem_resource = {
42 .name = "PCI mem",
43 .start = 0,
44 .end = -1,
45 .flags = IORESOURCE_MEM,
46};
47EXPORT_SYMBOL(iomem_resource);
48
49/* constraints to be met while allocating resources */
50struct resource_constraint {
51 resource_size_t min, max, align;
52 resource_size_t (*alignf)(void *, const struct resource *,
53 resource_size_t, resource_size_t);
54 void *alignf_data;
55};
56
57static DEFINE_RWLOCK(resource_lock);
58
59/*
60 * For memory hotplug, there is no way to free resource entries allocated
61 * by boot mem after the system is up. So for reusing the resource entry
62 * we need to remember the resource.
63 */
64static struct resource *bootmem_resource_free;
65static DEFINE_SPINLOCK(bootmem_resource_lock);
66
67static struct resource *next_resource(struct resource *p, bool sibling_only)
68{
69 /* Caller wants to traverse through siblings only */
70 if (sibling_only)
71 return p->sibling;
72
73 if (p->child)
74 return p->child;
75 while (!p->sibling && p->parent)
76 p = p->parent;
77 return p->sibling;
78}
79
80static void *r_next(struct seq_file *m, void *v, loff_t *pos)
81{
82 struct resource *p = v;
83 (*pos)++;
84 return (void *)next_resource(p, false);
85}
86
87#ifdef CONFIG_PROC_FS
88
89enum { MAX_IORES_LEVEL = 5 };
90
91static void *r_start(struct seq_file *m, loff_t *pos)
92 __acquires(resource_lock)
93{
94 struct resource *p = PDE_DATA(file_inode(m->file));
95 loff_t l = 0;
96 read_lock(&resource_lock);
97 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
98 ;
99 return p;
100}
101
102static void r_stop(struct seq_file *m, void *v)
103 __releases(resource_lock)
104{
105 read_unlock(&resource_lock);
106}
107
108static int r_show(struct seq_file *m, void *v)
109{
110 struct resource *root = PDE_DATA(file_inode(m->file));
111 struct resource *r = v, *p;
112 unsigned long long start, end;
113 int width = root->end < 0x10000 ? 4 : 8;
114 int depth;
115
116 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
117 if (p->parent == root)
118 break;
119
120 if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
121 start = r->start;
122 end = r->end;
123 } else {
124 start = end = 0;
125 }
126
127 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
128 depth * 2, "",
129 width, start,
130 width, end,
131 r->name ? r->name : "<BAD>");
132 return 0;
133}
134
135static const struct seq_operations resource_op = {
136 .start = r_start,
137 .next = r_next,
138 .stop = r_stop,
139 .show = r_show,
140};
141
142static int __init ioresources_init(void)
143{
144 proc_create_seq_data("ioports", 0, NULL, &resource_op,
145 &ioport_resource);
146 proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource);
147 return 0;
148}
149__initcall(ioresources_init);
150
151#endif /* CONFIG_PROC_FS */
152
153static void free_resource(struct resource *res)
154{
155 if (!res)
156 return;
157
158 if (!PageSlab(virt_to_head_page(res))) {
159 spin_lock(&bootmem_resource_lock);
160 res->sibling = bootmem_resource_free;
161 bootmem_resource_free = res;
162 spin_unlock(&bootmem_resource_lock);
163 } else {
164 kfree(res);
165 }
166}
167
168static struct resource *alloc_resource(gfp_t flags)
169{
170 struct resource *res = NULL;
171
172 spin_lock(&bootmem_resource_lock);
173 if (bootmem_resource_free) {
174 res = bootmem_resource_free;
175 bootmem_resource_free = res->sibling;
176 }
177 spin_unlock(&bootmem_resource_lock);
178
179 if (res)
180 memset(res, 0, sizeof(struct resource));
181 else
182 res = kzalloc(sizeof(struct resource), flags);
183
184 return res;
185}
186
187/* Return the conflict entry if you can't request it */
188static struct resource * __request_resource(struct resource *root, struct resource *new)
189{
190 resource_size_t start = new->start;
191 resource_size_t end = new->end;
192 struct resource *tmp, **p;
193
194 if (end < start)
195 return root;
196 if (start < root->start)
197 return root;
198 if (end > root->end)
199 return root;
200 p = &root->child;
201 for (;;) {
202 tmp = *p;
203 if (!tmp || tmp->start > end) {
204 new->sibling = tmp;
205 *p = new;
206 new->parent = root;
207 return NULL;
208 }
209 p = &tmp->sibling;
210 if (tmp->end < start)
211 continue;
212 return tmp;
213 }
214}
215
216static int __release_resource(struct resource *old, bool release_child)
217{
218 struct resource *tmp, **p, *chd;
219
220 p = &old->parent->child;
221 for (;;) {
222 tmp = *p;
223 if (!tmp)
224 break;
225 if (tmp == old) {
226 if (release_child || !(tmp->child)) {
227 *p = tmp->sibling;
228 } else {
229 for (chd = tmp->child;; chd = chd->sibling) {
230 chd->parent = tmp->parent;
231 if (!(chd->sibling))
232 break;
233 }
234 *p = tmp->child;
235 chd->sibling = tmp->sibling;
236 }
237 old->parent = NULL;
238 return 0;
239 }
240 p = &tmp->sibling;
241 }
242 return -EINVAL;
243}
244
245static void __release_child_resources(struct resource *r)
246{
247 struct resource *tmp, *p;
248 resource_size_t size;
249
250 p = r->child;
251 r->child = NULL;
252 while (p) {
253 tmp = p;
254 p = p->sibling;
255
256 tmp->parent = NULL;
257 tmp->sibling = NULL;
258 __release_child_resources(tmp);
259
260 printk(KERN_DEBUG "release child resource %pR\n", tmp);
261 /* need to restore size, and keep flags */
262 size = resource_size(tmp);
263 tmp->start = 0;
264 tmp->end = size - 1;
265 }
266}
267
268void release_child_resources(struct resource *r)
269{
270 write_lock(&resource_lock);
271 __release_child_resources(r);
272 write_unlock(&resource_lock);
273}
274
275/**
276 * request_resource_conflict - request and reserve an I/O or memory resource
277 * @root: root resource descriptor
278 * @new: resource descriptor desired by caller
279 *
280 * Returns 0 for success, conflict resource on error.
281 */
282struct resource *request_resource_conflict(struct resource *root, struct resource *new)
283{
284 struct resource *conflict;
285
286 write_lock(&resource_lock);
287 conflict = __request_resource(root, new);
288 write_unlock(&resource_lock);
289 return conflict;
290}
291
292/**
293 * request_resource - request and reserve an I/O or memory resource
294 * @root: root resource descriptor
295 * @new: resource descriptor desired by caller
296 *
297 * Returns 0 for success, negative error code on error.
298 */
299int request_resource(struct resource *root, struct resource *new)
300{
301 struct resource *conflict;
302
303 conflict = request_resource_conflict(root, new);
304 return conflict ? -EBUSY : 0;
305}
306
307EXPORT_SYMBOL(request_resource);
308
309/**
310 * release_resource - release a previously reserved resource
311 * @old: resource pointer
312 */
313int release_resource(struct resource *old)
314{
315 int retval;
316
317 write_lock(&resource_lock);
318 retval = __release_resource(old, true);
319 write_unlock(&resource_lock);
320 return retval;
321}
322
323EXPORT_SYMBOL(release_resource);
324
325/**
326 * find_next_iomem_res - Finds the lowest iomem resource that covers part of
327 * [@start..@end].
328 *
329 * If a resource is found, returns 0 and @*res is overwritten with the part
330 * of the resource that's within [@start..@end]; if none is found, returns
331 * -ENODEV. Returns -EINVAL for invalid parameters.
332 *
333 * This function walks the whole tree and not just first level children
334 * unless @first_lvl is true.
335 *
336 * @start: start address of the resource searched for
337 * @end: end address of same resource
338 * @flags: flags which the resource must have
339 * @desc: descriptor the resource must have
340 * @first_lvl: walk only the first level children, if set
341 * @res: return ptr, if resource found
342 *
343 * The caller must specify @start, @end, @flags, and @desc
344 * (which may be IORES_DESC_NONE).
345 */
346static int find_next_iomem_res(resource_size_t start, resource_size_t end,
347 unsigned long flags, unsigned long desc,
348 bool first_lvl, struct resource *res)
349{
350 bool siblings_only = true;
351 struct resource *p;
352
353 if (!res)
354 return -EINVAL;
355
356 if (start >= end)
357 return -EINVAL;
358
359 read_lock(&resource_lock);
360
361 for (p = iomem_resource.child; p; p = next_resource(p, siblings_only)) {
362 /* If we passed the resource we are looking for, stop */
363 if (p->start > end) {
364 p = NULL;
365 break;
366 }
367
368 /* Skip until we find a range that matches what we look for */
369 if (p->end < start)
370 continue;
371
372 /*
373 * Now that we found a range that matches what we look for,
374 * check the flags and the descriptor. If we were not asked to
375 * use only the first level, start looking at children as well.
376 */
377 siblings_only = first_lvl;
378
379 if ((p->flags & flags) != flags)
380 continue;
381 if ((desc != IORES_DESC_NONE) && (desc != p->desc))
382 continue;
383
384 /* Found a match, break */
385 break;
386 }
387
388 if (p) {
389 /* copy data */
390 *res = (struct resource) {
391 .start = max(start, p->start),
392 .end = min(end, p->end),
393 .flags = p->flags,
394 .desc = p->desc,
395 .parent = p->parent,
396 };
397 }
398
399 read_unlock(&resource_lock);
400 return p ? 0 : -ENODEV;
401}
402
403static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
404 unsigned long flags, unsigned long desc,
405 bool first_lvl, void *arg,
406 int (*func)(struct resource *, void *))
407{
408 struct resource res;
409 int ret = -EINVAL;
410
411 while (start < end &&
412 !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) {
413 ret = (*func)(&res, arg);
414 if (ret)
415 break;
416
417 start = res.end + 1;
418 }
419
420 return ret;
421}
422
423/**
424 * walk_iomem_res_desc - Walks through iomem resources and calls func()
425 * with matching resource ranges.
426 * *
427 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
428 * @flags: I/O resource flags
429 * @start: start addr
430 * @end: end addr
431 * @arg: function argument for the callback @func
432 * @func: callback function that is called for each qualifying resource area
433 *
434 * This walks through whole tree and not just first level children.
435 * All the memory ranges which overlap start,end and also match flags and
436 * desc are valid candidates.
437 *
438 * NOTE: For a new descriptor search, define a new IORES_DESC in
439 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
440 */
441int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
442 u64 end, void *arg, int (*func)(struct resource *, void *))
443{
444 return __walk_iomem_res_desc(start, end, flags, desc, false, arg, func);
445}
446EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
447
448/*
449 * This function calls the @func callback against all memory ranges of type
450 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
451 * Now, this function is only for System RAM, it deals with full ranges and
452 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
453 * ranges.
454 */
455int walk_system_ram_res(u64 start, u64 end, void *arg,
456 int (*func)(struct resource *, void *))
457{
458 unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
459
460 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
461 arg, func);
462}
463
464/*
465 * This function calls the @func callback against all memory ranges, which
466 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
467 */
468int walk_mem_res(u64 start, u64 end, void *arg,
469 int (*func)(struct resource *, void *))
470{
471 unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
472
473 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
474 arg, func);
475}
476
477/*
478 * This function calls the @func callback against all memory ranges of type
479 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
480 * It is to be used only for System RAM.
481 *
482 * This will find System RAM ranges that are children of top-level resources
483 * in addition to top-level System RAM resources.
484 */
485int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
486 void *arg, int (*func)(unsigned long, unsigned long, void *))
487{
488 resource_size_t start, end;
489 unsigned long flags;
490 struct resource res;
491 unsigned long pfn, end_pfn;
492 int ret = -EINVAL;
493
494 start = (u64) start_pfn << PAGE_SHIFT;
495 end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
496 flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
497 while (start < end &&
498 !find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
499 false, &res)) {
500 pfn = PFN_UP(res.start);
501 end_pfn = PFN_DOWN(res.end + 1);
502 if (end_pfn > pfn)
503 ret = (*func)(pfn, end_pfn - pfn, arg);
504 if (ret)
505 break;
506 start = res.end + 1;
507 }
508 return ret;
509}
510
511static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
512{
513 return 1;
514}
515
516/*
517 * This generic page_is_ram() returns true if specified address is
518 * registered as System RAM in iomem_resource list.
519 */
520int __weak page_is_ram(unsigned long pfn)
521{
522 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
523}
524EXPORT_SYMBOL_GPL(page_is_ram);
525
526/**
527 * region_intersects() - determine intersection of region with known resources
528 * @start: region start address
529 * @size: size of region
530 * @flags: flags of resource (in iomem_resource)
531 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
532 *
533 * Check if the specified region partially overlaps or fully eclipses a
534 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
535 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
536 * return REGION_MIXED if the region overlaps @flags/@desc and another
537 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
538 * and no other defined resource. Note that REGION_INTERSECTS is also
539 * returned in the case when the specified region overlaps RAM and undefined
540 * memory holes.
541 *
542 * region_intersect() is used by memory remapping functions to ensure
543 * the user is not remapping RAM and is a vast speed up over walking
544 * through the resource table page by page.
545 */
546int region_intersects(resource_size_t start, size_t size, unsigned long flags,
547 unsigned long desc)
548{
549 struct resource res;
550 int type = 0; int other = 0;
551 struct resource *p;
552
553 res.start = start;
554 res.end = start + size - 1;
555
556 read_lock(&resource_lock);
557 for (p = iomem_resource.child; p ; p = p->sibling) {
558 bool is_type = (((p->flags & flags) == flags) &&
559 ((desc == IORES_DESC_NONE) ||
560 (desc == p->desc)));
561
562 if (resource_overlaps(p, &res))
563 is_type ? type++ : other++;
564 }
565 read_unlock(&resource_lock);
566
567 if (type == 0)
568 return REGION_DISJOINT;
569
570 if (other == 0)
571 return REGION_INTERSECTS;
572
573 return REGION_MIXED;
574}
575EXPORT_SYMBOL_GPL(region_intersects);
576
577void __weak arch_remove_reservations(struct resource *avail)
578{
579}
580
581static resource_size_t simple_align_resource(void *data,
582 const struct resource *avail,
583 resource_size_t size,
584 resource_size_t align)
585{
586 return avail->start;
587}
588
589static void resource_clip(struct resource *res, resource_size_t min,
590 resource_size_t max)
591{
592 if (res->start < min)
593 res->start = min;
594 if (res->end > max)
595 res->end = max;
596}
597
598/*
599 * Find empty slot in the resource tree with the given range and
600 * alignment constraints
601 */
602static int __find_resource(struct resource *root, struct resource *old,
603 struct resource *new,
604 resource_size_t size,
605 struct resource_constraint *constraint)
606{
607 struct resource *this = root->child;
608 struct resource tmp = *new, avail, alloc;
609
610 tmp.start = root->start;
611 /*
612 * Skip past an allocated resource that starts at 0, since the assignment
613 * of this->start - 1 to tmp->end below would cause an underflow.
614 */
615 if (this && this->start == root->start) {
616 tmp.start = (this == old) ? old->start : this->end + 1;
617 this = this->sibling;
618 }
619 for(;;) {
620 if (this)
621 tmp.end = (this == old) ? this->end : this->start - 1;
622 else
623 tmp.end = root->end;
624
625 if (tmp.end < tmp.start)
626 goto next;
627
628 resource_clip(&tmp, constraint->min, constraint->max);
629 arch_remove_reservations(&tmp);
630
631 /* Check for overflow after ALIGN() */
632 avail.start = ALIGN(tmp.start, constraint->align);
633 avail.end = tmp.end;
634 avail.flags = new->flags & ~IORESOURCE_UNSET;
635 if (avail.start >= tmp.start) {
636 alloc.flags = avail.flags;
637 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
638 size, constraint->align);
639 alloc.end = alloc.start + size - 1;
640 if (alloc.start <= alloc.end &&
641 resource_contains(&avail, &alloc)) {
642 new->start = alloc.start;
643 new->end = alloc.end;
644 return 0;
645 }
646 }
647
648next: if (!this || this->end == root->end)
649 break;
650
651 if (this != old)
652 tmp.start = this->end + 1;
653 this = this->sibling;
654 }
655 return -EBUSY;
656}
657
658/*
659 * Find empty slot in the resource tree given range and alignment.
660 */
661static int find_resource(struct resource *root, struct resource *new,
662 resource_size_t size,
663 struct resource_constraint *constraint)
664{
665 return __find_resource(root, NULL, new, size, constraint);
666}
667
668/**
669 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
670 * The resource will be relocated if the new size cannot be reallocated in the
671 * current location.
672 *
673 * @root: root resource descriptor
674 * @old: resource descriptor desired by caller
675 * @newsize: new size of the resource descriptor
676 * @constraint: the size and alignment constraints to be met.
677 */
678static int reallocate_resource(struct resource *root, struct resource *old,
679 resource_size_t newsize,
680 struct resource_constraint *constraint)
681{
682 int err=0;
683 struct resource new = *old;
684 struct resource *conflict;
685
686 write_lock(&resource_lock);
687
688 if ((err = __find_resource(root, old, &new, newsize, constraint)))
689 goto out;
690
691 if (resource_contains(&new, old)) {
692 old->start = new.start;
693 old->end = new.end;
694 goto out;
695 }
696
697 if (old->child) {
698 err = -EBUSY;
699 goto out;
700 }
701
702 if (resource_contains(old, &new)) {
703 old->start = new.start;
704 old->end = new.end;
705 } else {
706 __release_resource(old, true);
707 *old = new;
708 conflict = __request_resource(root, old);
709 BUG_ON(conflict);
710 }
711out:
712 write_unlock(&resource_lock);
713 return err;
714}
715
716
717/**
718 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
719 * The resource will be reallocated with a new size if it was already allocated
720 * @root: root resource descriptor
721 * @new: resource descriptor desired by caller
722 * @size: requested resource region size
723 * @min: minimum boundary to allocate
724 * @max: maximum boundary to allocate
725 * @align: alignment requested, in bytes
726 * @alignf: alignment function, optional, called if not NULL
727 * @alignf_data: arbitrary data to pass to the @alignf function
728 */
729int allocate_resource(struct resource *root, struct resource *new,
730 resource_size_t size, resource_size_t min,
731 resource_size_t max, resource_size_t align,
732 resource_size_t (*alignf)(void *,
733 const struct resource *,
734 resource_size_t,
735 resource_size_t),
736 void *alignf_data)
737{
738 int err;
739 struct resource_constraint constraint;
740
741 if (!alignf)
742 alignf = simple_align_resource;
743
744 constraint.min = min;
745 constraint.max = max;
746 constraint.align = align;
747 constraint.alignf = alignf;
748 constraint.alignf_data = alignf_data;
749
750 if ( new->parent ) {
751 /* resource is already allocated, try reallocating with
752 the new constraints */
753 return reallocate_resource(root, new, size, &constraint);
754 }
755
756 write_lock(&resource_lock);
757 err = find_resource(root, new, size, &constraint);
758 if (err >= 0 && __request_resource(root, new))
759 err = -EBUSY;
760 write_unlock(&resource_lock);
761 return err;
762}
763
764EXPORT_SYMBOL(allocate_resource);
765
766/**
767 * lookup_resource - find an existing resource by a resource start address
768 * @root: root resource descriptor
769 * @start: resource start address
770 *
771 * Returns a pointer to the resource if found, NULL otherwise
772 */
773struct resource *lookup_resource(struct resource *root, resource_size_t start)
774{
775 struct resource *res;
776
777 read_lock(&resource_lock);
778 for (res = root->child; res; res = res->sibling) {
779 if (res->start == start)
780 break;
781 }
782 read_unlock(&resource_lock);
783
784 return res;
785}
786
787/*
788 * Insert a resource into the resource tree. If successful, return NULL,
789 * otherwise return the conflicting resource (compare to __request_resource())
790 */
791static struct resource * __insert_resource(struct resource *parent, struct resource *new)
792{
793 struct resource *first, *next;
794
795 for (;; parent = first) {
796 first = __request_resource(parent, new);
797 if (!first)
798 return first;
799
800 if (first == parent)
801 return first;
802 if (WARN_ON(first == new)) /* duplicated insertion */
803 return first;
804
805 if ((first->start > new->start) || (first->end < new->end))
806 break;
807 if ((first->start == new->start) && (first->end == new->end))
808 break;
809 }
810
811 for (next = first; ; next = next->sibling) {
812 /* Partial overlap? Bad, and unfixable */
813 if (next->start < new->start || next->end > new->end)
814 return next;
815 if (!next->sibling)
816 break;
817 if (next->sibling->start > new->end)
818 break;
819 }
820
821 new->parent = parent;
822 new->sibling = next->sibling;
823 new->child = first;
824
825 next->sibling = NULL;
826 for (next = first; next; next = next->sibling)
827 next->parent = new;
828
829 if (parent->child == first) {
830 parent->child = new;
831 } else {
832 next = parent->child;
833 while (next->sibling != first)
834 next = next->sibling;
835 next->sibling = new;
836 }
837 return NULL;
838}
839
840/**
841 * insert_resource_conflict - Inserts resource in the resource tree
842 * @parent: parent of the new resource
843 * @new: new resource to insert
844 *
845 * Returns 0 on success, conflict resource if the resource can't be inserted.
846 *
847 * This function is equivalent to request_resource_conflict when no conflict
848 * happens. If a conflict happens, and the conflicting resources
849 * entirely fit within the range of the new resource, then the new
850 * resource is inserted and the conflicting resources become children of
851 * the new resource.
852 *
853 * This function is intended for producers of resources, such as FW modules
854 * and bus drivers.
855 */
856struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
857{
858 struct resource *conflict;
859
860 write_lock(&resource_lock);
861 conflict = __insert_resource(parent, new);
862 write_unlock(&resource_lock);
863 return conflict;
864}
865
866/**
867 * insert_resource - Inserts a resource in the resource tree
868 * @parent: parent of the new resource
869 * @new: new resource to insert
870 *
871 * Returns 0 on success, -EBUSY if the resource can't be inserted.
872 *
873 * This function is intended for producers of resources, such as FW modules
874 * and bus drivers.
875 */
876int insert_resource(struct resource *parent, struct resource *new)
877{
878 struct resource *conflict;
879
880 conflict = insert_resource_conflict(parent, new);
881 return conflict ? -EBUSY : 0;
882}
883EXPORT_SYMBOL_GPL(insert_resource);
884
885/**
886 * insert_resource_expand_to_fit - Insert a resource into the resource tree
887 * @root: root resource descriptor
888 * @new: new resource to insert
889 *
890 * Insert a resource into the resource tree, possibly expanding it in order
891 * to make it encompass any conflicting resources.
892 */
893void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
894{
895 if (new->parent)
896 return;
897
898 write_lock(&resource_lock);
899 for (;;) {
900 struct resource *conflict;
901
902 conflict = __insert_resource(root, new);
903 if (!conflict)
904 break;
905 if (conflict == root)
906 break;
907
908 /* Ok, expand resource to cover the conflict, then try again .. */
909 if (conflict->start < new->start)
910 new->start = conflict->start;
911 if (conflict->end > new->end)
912 new->end = conflict->end;
913
914 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
915 }
916 write_unlock(&resource_lock);
917}
918
919/**
920 * remove_resource - Remove a resource in the resource tree
921 * @old: resource to remove
922 *
923 * Returns 0 on success, -EINVAL if the resource is not valid.
924 *
925 * This function removes a resource previously inserted by insert_resource()
926 * or insert_resource_conflict(), and moves the children (if any) up to
927 * where they were before. insert_resource() and insert_resource_conflict()
928 * insert a new resource, and move any conflicting resources down to the
929 * children of the new resource.
930 *
931 * insert_resource(), insert_resource_conflict() and remove_resource() are
932 * intended for producers of resources, such as FW modules and bus drivers.
933 */
934int remove_resource(struct resource *old)
935{
936 int retval;
937
938 write_lock(&resource_lock);
939 retval = __release_resource(old, false);
940 write_unlock(&resource_lock);
941 return retval;
942}
943EXPORT_SYMBOL_GPL(remove_resource);
944
945static int __adjust_resource(struct resource *res, resource_size_t start,
946 resource_size_t size)
947{
948 struct resource *tmp, *parent = res->parent;
949 resource_size_t end = start + size - 1;
950 int result = -EBUSY;
951
952 if (!parent)
953 goto skip;
954
955 if ((start < parent->start) || (end > parent->end))
956 goto out;
957
958 if (res->sibling && (res->sibling->start <= end))
959 goto out;
960
961 tmp = parent->child;
962 if (tmp != res) {
963 while (tmp->sibling != res)
964 tmp = tmp->sibling;
965 if (start <= tmp->end)
966 goto out;
967 }
968
969skip:
970 for (tmp = res->child; tmp; tmp = tmp->sibling)
971 if ((tmp->start < start) || (tmp->end > end))
972 goto out;
973
974 res->start = start;
975 res->end = end;
976 result = 0;
977
978 out:
979 return result;
980}
981
982/**
983 * adjust_resource - modify a resource's start and size
984 * @res: resource to modify
985 * @start: new start value
986 * @size: new size
987 *
988 * Given an existing resource, change its start and size to match the
989 * arguments. Returns 0 on success, -EBUSY if it can't fit.
990 * Existing children of the resource are assumed to be immutable.
991 */
992int adjust_resource(struct resource *res, resource_size_t start,
993 resource_size_t size)
994{
995 int result;
996
997 write_lock(&resource_lock);
998 result = __adjust_resource(res, start, size);
999 write_unlock(&resource_lock);
1000 return result;
1001}
1002EXPORT_SYMBOL(adjust_resource);
1003
1004static void __init
1005__reserve_region_with_split(struct resource *root, resource_size_t start,
1006 resource_size_t end, const char *name)
1007{
1008 struct resource *parent = root;
1009 struct resource *conflict;
1010 struct resource *res = alloc_resource(GFP_ATOMIC);
1011 struct resource *next_res = NULL;
1012 int type = resource_type(root);
1013
1014 if (!res)
1015 return;
1016
1017 res->name = name;
1018 res->start = start;
1019 res->end = end;
1020 res->flags = type | IORESOURCE_BUSY;
1021 res->desc = IORES_DESC_NONE;
1022
1023 while (1) {
1024
1025 conflict = __request_resource(parent, res);
1026 if (!conflict) {
1027 if (!next_res)
1028 break;
1029 res = next_res;
1030 next_res = NULL;
1031 continue;
1032 }
1033
1034 /* conflict covered whole area */
1035 if (conflict->start <= res->start &&
1036 conflict->end >= res->end) {
1037 free_resource(res);
1038 WARN_ON(next_res);
1039 break;
1040 }
1041
1042 /* failed, split and try again */
1043 if (conflict->start > res->start) {
1044 end = res->end;
1045 res->end = conflict->start - 1;
1046 if (conflict->end < end) {
1047 next_res = alloc_resource(GFP_ATOMIC);
1048 if (!next_res) {
1049 free_resource(res);
1050 break;
1051 }
1052 next_res->name = name;
1053 next_res->start = conflict->end + 1;
1054 next_res->end = end;
1055 next_res->flags = type | IORESOURCE_BUSY;
1056 next_res->desc = IORES_DESC_NONE;
1057 }
1058 } else {
1059 res->start = conflict->end + 1;
1060 }
1061 }
1062
1063}
1064
1065void __init
1066reserve_region_with_split(struct resource *root, resource_size_t start,
1067 resource_size_t end, const char *name)
1068{
1069 int abort = 0;
1070
1071 write_lock(&resource_lock);
1072 if (root->start > start || root->end < end) {
1073 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1074 (unsigned long long)start, (unsigned long long)end,
1075 root);
1076 if (start > root->end || end < root->start)
1077 abort = 1;
1078 else {
1079 if (end > root->end)
1080 end = root->end;
1081 if (start < root->start)
1082 start = root->start;
1083 pr_err("fixing request to [0x%llx-0x%llx]\n",
1084 (unsigned long long)start,
1085 (unsigned long long)end);
1086 }
1087 dump_stack();
1088 }
1089 if (!abort)
1090 __reserve_region_with_split(root, start, end, name);
1091 write_unlock(&resource_lock);
1092}
1093
1094/**
1095 * resource_alignment - calculate resource's alignment
1096 * @res: resource pointer
1097 *
1098 * Returns alignment on success, 0 (invalid alignment) on failure.
1099 */
1100resource_size_t resource_alignment(struct resource *res)
1101{
1102 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1103 case IORESOURCE_SIZEALIGN:
1104 return resource_size(res);
1105 case IORESOURCE_STARTALIGN:
1106 return res->start;
1107 default:
1108 return 0;
1109 }
1110}
1111
1112/*
1113 * This is compatibility stuff for IO resources.
1114 *
1115 * Note how this, unlike the above, knows about
1116 * the IO flag meanings (busy etc).
1117 *
1118 * request_region creates a new busy region.
1119 *
1120 * release_region releases a matching busy region.
1121 */
1122
1123static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1124
1125static struct inode *iomem_inode;
1126
1127#ifdef CONFIG_IO_STRICT_DEVMEM
1128static void revoke_iomem(struct resource *res)
1129{
1130 /* pairs with smp_store_release() in iomem_init_inode() */
1131 struct inode *inode = smp_load_acquire(&iomem_inode);
1132
1133 /*
1134 * Check that the initialization has completed. Losing the race
1135 * is ok because it means drivers are claiming resources before
1136 * the fs_initcall level of init and prevent iomem_get_mapping users
1137 * from establishing mappings.
1138 */
1139 if (!inode)
1140 return;
1141
1142 /*
1143 * The expectation is that the driver has successfully marked
1144 * the resource busy by this point, so devmem_is_allowed()
1145 * should start returning false, however for performance this
1146 * does not iterate the entire resource range.
1147 */
1148 if (devmem_is_allowed(PHYS_PFN(res->start)) &&
1149 devmem_is_allowed(PHYS_PFN(res->end))) {
1150 /*
1151 * *cringe* iomem=relaxed says "go ahead, what's the
1152 * worst that can happen?"
1153 */
1154 return;
1155 }
1156
1157 unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1);
1158}
1159#else
1160static void revoke_iomem(struct resource *res) {}
1161#endif
1162
1163struct address_space *iomem_get_mapping(void)
1164{
1165 /*
1166 * This function is only called from file open paths, hence guaranteed
1167 * that fs_initcalls have completed and no need to check for NULL. But
1168 * since revoke_iomem can be called before the initcall we still need
1169 * the barrier to appease checkers.
1170 */
1171 return smp_load_acquire(&iomem_inode)->i_mapping;
1172}
1173
1174/**
1175 * __request_region - create a new busy resource region
1176 * @parent: parent resource descriptor
1177 * @start: resource start address
1178 * @n: resource region size
1179 * @name: reserving caller's ID string
1180 * @flags: IO resource flags
1181 */
1182struct resource * __request_region(struct resource *parent,
1183 resource_size_t start, resource_size_t n,
1184 const char *name, int flags)
1185{
1186 DECLARE_WAITQUEUE(wait, current);
1187 struct resource *res = alloc_resource(GFP_KERNEL);
1188 struct resource *orig_parent = parent;
1189
1190 if (!res)
1191 return NULL;
1192
1193 res->name = name;
1194 res->start = start;
1195 res->end = start + n - 1;
1196
1197 write_lock(&resource_lock);
1198
1199 for (;;) {
1200 struct resource *conflict;
1201
1202 res->flags = resource_type(parent) | resource_ext_type(parent);
1203 res->flags |= IORESOURCE_BUSY | flags;
1204 res->desc = parent->desc;
1205
1206 conflict = __request_resource(parent, res);
1207 if (!conflict)
1208 break;
1209 /*
1210 * mm/hmm.c reserves physical addresses which then
1211 * become unavailable to other users. Conflicts are
1212 * not expected. Warn to aid debugging if encountered.
1213 */
1214 if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1215 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1216 conflict->name, conflict, res);
1217 }
1218 if (conflict != parent) {
1219 if (!(conflict->flags & IORESOURCE_BUSY)) {
1220 parent = conflict;
1221 continue;
1222 }
1223 }
1224 if (conflict->flags & flags & IORESOURCE_MUXED) {
1225 add_wait_queue(&muxed_resource_wait, &wait);
1226 write_unlock(&resource_lock);
1227 set_current_state(TASK_UNINTERRUPTIBLE);
1228 schedule();
1229 remove_wait_queue(&muxed_resource_wait, &wait);
1230 write_lock(&resource_lock);
1231 continue;
1232 }
1233 /* Uhhuh, that didn't work out.. */
1234 free_resource(res);
1235 res = NULL;
1236 break;
1237 }
1238 write_unlock(&resource_lock);
1239
1240 if (res && orig_parent == &iomem_resource)
1241 revoke_iomem(res);
1242
1243 return res;
1244}
1245EXPORT_SYMBOL(__request_region);
1246
1247/**
1248 * __release_region - release a previously reserved resource region
1249 * @parent: parent resource descriptor
1250 * @start: resource start address
1251 * @n: resource region size
1252 *
1253 * The described resource region must match a currently busy region.
1254 */
1255void __release_region(struct resource *parent, resource_size_t start,
1256 resource_size_t n)
1257{
1258 struct resource **p;
1259 resource_size_t end;
1260
1261 p = &parent->child;
1262 end = start + n - 1;
1263
1264 write_lock(&resource_lock);
1265
1266 for (;;) {
1267 struct resource *res = *p;
1268
1269 if (!res)
1270 break;
1271 if (res->start <= start && res->end >= end) {
1272 if (!(res->flags & IORESOURCE_BUSY)) {
1273 p = &res->child;
1274 continue;
1275 }
1276 if (res->start != start || res->end != end)
1277 break;
1278 *p = res->sibling;
1279 write_unlock(&resource_lock);
1280 if (res->flags & IORESOURCE_MUXED)
1281 wake_up(&muxed_resource_wait);
1282 free_resource(res);
1283 return;
1284 }
1285 p = &res->sibling;
1286 }
1287
1288 write_unlock(&resource_lock);
1289
1290 printk(KERN_WARNING "Trying to free nonexistent resource "
1291 "<%016llx-%016llx>\n", (unsigned long long)start,
1292 (unsigned long long)end);
1293}
1294EXPORT_SYMBOL(__release_region);
1295
1296#ifdef CONFIG_MEMORY_HOTREMOVE
1297/**
1298 * release_mem_region_adjustable - release a previously reserved memory region
1299 * @start: resource start address
1300 * @size: resource region size
1301 *
1302 * This interface is intended for memory hot-delete. The requested region
1303 * is released from a currently busy memory resource. The requested region
1304 * must either match exactly or fit into a single busy resource entry. In
1305 * the latter case, the remaining resource is adjusted accordingly.
1306 * Existing children of the busy memory resource must be immutable in the
1307 * request.
1308 *
1309 * Note:
1310 * - Additional release conditions, such as overlapping region, can be
1311 * supported after they are confirmed as valid cases.
1312 * - When a busy memory resource gets split into two entries, the code
1313 * assumes that all children remain in the lower address entry for
1314 * simplicity. Enhance this logic when necessary.
1315 */
1316void release_mem_region_adjustable(resource_size_t start, resource_size_t size)
1317{
1318 struct resource *parent = &iomem_resource;
1319 struct resource *new_res = NULL;
1320 bool alloc_nofail = false;
1321 struct resource **p;
1322 struct resource *res;
1323 resource_size_t end;
1324
1325 end = start + size - 1;
1326 if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
1327 return;
1328
1329 /*
1330 * We free up quite a lot of memory on memory hotunplug (esp., memap),
1331 * just before releasing the region. This is highly unlikely to
1332 * fail - let's play save and make it never fail as the caller cannot
1333 * perform any error handling (e.g., trying to re-add memory will fail
1334 * similarly).
1335 */
1336retry:
1337 new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
1338
1339 p = &parent->child;
1340 write_lock(&resource_lock);
1341
1342 while ((res = *p)) {
1343 if (res->start >= end)
1344 break;
1345
1346 /* look for the next resource if it does not fit into */
1347 if (res->start > start || res->end < end) {
1348 p = &res->sibling;
1349 continue;
1350 }
1351
1352 /*
1353 * All memory regions added from memory-hotplug path have the
1354 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1355 * this flag, we know that we are dealing with a resource coming
1356 * from HMM/devm. HMM/devm use another mechanism to add/release
1357 * a resource. This goes via devm_request_mem_region and
1358 * devm_release_mem_region.
1359 * HMM/devm take care to release their resources when they want,
1360 * so if we are dealing with them, let us just back off here.
1361 */
1362 if (!(res->flags & IORESOURCE_SYSRAM)) {
1363 break;
1364 }
1365
1366 if (!(res->flags & IORESOURCE_MEM))
1367 break;
1368
1369 if (!(res->flags & IORESOURCE_BUSY)) {
1370 p = &res->child;
1371 continue;
1372 }
1373
1374 /* found the target resource; let's adjust accordingly */
1375 if (res->start == start && res->end == end) {
1376 /* free the whole entry */
1377 *p = res->sibling;
1378 free_resource(res);
1379 } else if (res->start == start && res->end != end) {
1380 /* adjust the start */
1381 WARN_ON_ONCE(__adjust_resource(res, end + 1,
1382 res->end - end));
1383 } else if (res->start != start && res->end == end) {
1384 /* adjust the end */
1385 WARN_ON_ONCE(__adjust_resource(res, res->start,
1386 start - res->start));
1387 } else {
1388 /* split into two entries - we need a new resource */
1389 if (!new_res) {
1390 new_res = alloc_resource(GFP_ATOMIC);
1391 if (!new_res) {
1392 alloc_nofail = true;
1393 write_unlock(&resource_lock);
1394 goto retry;
1395 }
1396 }
1397 new_res->name = res->name;
1398 new_res->start = end + 1;
1399 new_res->end = res->end;
1400 new_res->flags = res->flags;
1401 new_res->desc = res->desc;
1402 new_res->parent = res->parent;
1403 new_res->sibling = res->sibling;
1404 new_res->child = NULL;
1405
1406 if (WARN_ON_ONCE(__adjust_resource(res, res->start,
1407 start - res->start)))
1408 break;
1409 res->sibling = new_res;
1410 new_res = NULL;
1411 }
1412
1413 break;
1414 }
1415
1416 write_unlock(&resource_lock);
1417 free_resource(new_res);
1418}
1419#endif /* CONFIG_MEMORY_HOTREMOVE */
1420
1421#ifdef CONFIG_MEMORY_HOTPLUG
1422static bool system_ram_resources_mergeable(struct resource *r1,
1423 struct resource *r2)
1424{
1425 /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1426 return r1->flags == r2->flags && r1->end + 1 == r2->start &&
1427 r1->name == r2->name && r1->desc == r2->desc &&
1428 !r1->child && !r2->child;
1429}
1430
1431/**
1432 * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1433 * merge it with adjacent, mergeable resources
1434 * @res: resource descriptor
1435 *
1436 * This interface is intended for memory hotplug, whereby lots of contiguous
1437 * system ram resources are added (e.g., via add_memory*()) by a driver, and
1438 * the actual resource boundaries are not of interest (e.g., it might be
1439 * relevant for DIMMs). Only resources that are marked mergeable, that have the
1440 * same parent, and that don't have any children are considered. All mergeable
1441 * resources must be immutable during the request.
1442 *
1443 * Note:
1444 * - The caller has to make sure that no pointers to resources that are
1445 * marked mergeable are used anymore after this call - the resource might
1446 * be freed and the pointer might be stale!
1447 * - release_mem_region_adjustable() will split on demand on memory hotunplug
1448 */
1449void merge_system_ram_resource(struct resource *res)
1450{
1451 const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
1452 struct resource *cur;
1453
1454 if (WARN_ON_ONCE((res->flags & flags) != flags))
1455 return;
1456
1457 write_lock(&resource_lock);
1458 res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
1459
1460 /* Try to merge with next item in the list. */
1461 cur = res->sibling;
1462 if (cur && system_ram_resources_mergeable(res, cur)) {
1463 res->end = cur->end;
1464 res->sibling = cur->sibling;
1465 free_resource(cur);
1466 }
1467
1468 /* Try to merge with previous item in the list. */
1469 cur = res->parent->child;
1470 while (cur && cur->sibling != res)
1471 cur = cur->sibling;
1472 if (cur && system_ram_resources_mergeable(cur, res)) {
1473 cur->end = res->end;
1474 cur->sibling = res->sibling;
1475 free_resource(res);
1476 }
1477 write_unlock(&resource_lock);
1478}
1479#endif /* CONFIG_MEMORY_HOTPLUG */
1480
1481/*
1482 * Managed region resource
1483 */
1484static void devm_resource_release(struct device *dev, void *ptr)
1485{
1486 struct resource **r = ptr;
1487
1488 release_resource(*r);
1489}
1490
1491/**
1492 * devm_request_resource() - request and reserve an I/O or memory resource
1493 * @dev: device for which to request the resource
1494 * @root: root of the resource tree from which to request the resource
1495 * @new: descriptor of the resource to request
1496 *
1497 * This is a device-managed version of request_resource(). There is usually
1498 * no need to release resources requested by this function explicitly since
1499 * that will be taken care of when the device is unbound from its driver.
1500 * If for some reason the resource needs to be released explicitly, because
1501 * of ordering issues for example, drivers must call devm_release_resource()
1502 * rather than the regular release_resource().
1503 *
1504 * When a conflict is detected between any existing resources and the newly
1505 * requested resource, an error message will be printed.
1506 *
1507 * Returns 0 on success or a negative error code on failure.
1508 */
1509int devm_request_resource(struct device *dev, struct resource *root,
1510 struct resource *new)
1511{
1512 struct resource *conflict, **ptr;
1513
1514 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1515 if (!ptr)
1516 return -ENOMEM;
1517
1518 *ptr = new;
1519
1520 conflict = request_resource_conflict(root, new);
1521 if (conflict) {
1522 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1523 new, conflict->name, conflict);
1524 devres_free(ptr);
1525 return -EBUSY;
1526 }
1527
1528 devres_add(dev, ptr);
1529 return 0;
1530}
1531EXPORT_SYMBOL(devm_request_resource);
1532
1533static int devm_resource_match(struct device *dev, void *res, void *data)
1534{
1535 struct resource **ptr = res;
1536
1537 return *ptr == data;
1538}
1539
1540/**
1541 * devm_release_resource() - release a previously requested resource
1542 * @dev: device for which to release the resource
1543 * @new: descriptor of the resource to release
1544 *
1545 * Releases a resource previously requested using devm_request_resource().
1546 */
1547void devm_release_resource(struct device *dev, struct resource *new)
1548{
1549 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1550 new));
1551}
1552EXPORT_SYMBOL(devm_release_resource);
1553
1554struct region_devres {
1555 struct resource *parent;
1556 resource_size_t start;
1557 resource_size_t n;
1558};
1559
1560static void devm_region_release(struct device *dev, void *res)
1561{
1562 struct region_devres *this = res;
1563
1564 __release_region(this->parent, this->start, this->n);
1565}
1566
1567static int devm_region_match(struct device *dev, void *res, void *match_data)
1568{
1569 struct region_devres *this = res, *match = match_data;
1570
1571 return this->parent == match->parent &&
1572 this->start == match->start && this->n == match->n;
1573}
1574
1575struct resource *
1576__devm_request_region(struct device *dev, struct resource *parent,
1577 resource_size_t start, resource_size_t n, const char *name)
1578{
1579 struct region_devres *dr = NULL;
1580 struct resource *res;
1581
1582 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1583 GFP_KERNEL);
1584 if (!dr)
1585 return NULL;
1586
1587 dr->parent = parent;
1588 dr->start = start;
1589 dr->n = n;
1590
1591 res = __request_region(parent, start, n, name, 0);
1592 if (res)
1593 devres_add(dev, dr);
1594 else
1595 devres_free(dr);
1596
1597 return res;
1598}
1599EXPORT_SYMBOL(__devm_request_region);
1600
1601void __devm_release_region(struct device *dev, struct resource *parent,
1602 resource_size_t start, resource_size_t n)
1603{
1604 struct region_devres match_data = { parent, start, n };
1605
1606 __release_region(parent, start, n);
1607 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1608 &match_data));
1609}
1610EXPORT_SYMBOL(__devm_release_region);
1611
1612/*
1613 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1614 */
1615#define MAXRESERVE 4
1616static int __init reserve_setup(char *str)
1617{
1618 static int reserved;
1619 static struct resource reserve[MAXRESERVE];
1620
1621 for (;;) {
1622 unsigned int io_start, io_num;
1623 int x = reserved;
1624 struct resource *parent;
1625
1626 if (get_option(&str, &io_start) != 2)
1627 break;
1628 if (get_option(&str, &io_num) == 0)
1629 break;
1630 if (x < MAXRESERVE) {
1631 struct resource *res = reserve + x;
1632
1633 /*
1634 * If the region starts below 0x10000, we assume it's
1635 * I/O port space; otherwise assume it's memory.
1636 */
1637 if (io_start < 0x10000) {
1638 res->flags = IORESOURCE_IO;
1639 parent = &ioport_resource;
1640 } else {
1641 res->flags = IORESOURCE_MEM;
1642 parent = &iomem_resource;
1643 }
1644 res->name = "reserved";
1645 res->start = io_start;
1646 res->end = io_start + io_num - 1;
1647 res->flags |= IORESOURCE_BUSY;
1648 res->desc = IORES_DESC_NONE;
1649 res->child = NULL;
1650 if (request_resource(parent, res) == 0)
1651 reserved = x+1;
1652 }
1653 }
1654 return 1;
1655}
1656__setup("reserve=", reserve_setup);
1657
1658/*
1659 * Check if the requested addr and size spans more than any slot in the
1660 * iomem resource tree.
1661 */
1662int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1663{
1664 struct resource *p = &iomem_resource;
1665 int err = 0;
1666 loff_t l;
1667
1668 read_lock(&resource_lock);
1669 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1670 /*
1671 * We can probably skip the resources without
1672 * IORESOURCE_IO attribute?
1673 */
1674 if (p->start >= addr + size)
1675 continue;
1676 if (p->end < addr)
1677 continue;
1678 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1679 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1680 continue;
1681 /*
1682 * if a resource is "BUSY", it's not a hardware resource
1683 * but a driver mapping of such a resource; we don't want
1684 * to warn for those; some drivers legitimately map only
1685 * partial hardware resources. (example: vesafb)
1686 */
1687 if (p->flags & IORESOURCE_BUSY)
1688 continue;
1689
1690 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1691 (unsigned long long)addr,
1692 (unsigned long long)(addr + size - 1),
1693 p->name, p);
1694 err = -1;
1695 break;
1696 }
1697 read_unlock(&resource_lock);
1698
1699 return err;
1700}
1701
1702#ifdef CONFIG_STRICT_DEVMEM
1703static int strict_iomem_checks = 1;
1704#else
1705static int strict_iomem_checks;
1706#endif
1707
1708/*
1709 * check if an address is reserved in the iomem resource tree
1710 * returns true if reserved, false if not reserved.
1711 */
1712bool iomem_is_exclusive(u64 addr)
1713{
1714 struct resource *p = &iomem_resource;
1715 bool err = false;
1716 loff_t l;
1717 int size = PAGE_SIZE;
1718
1719 if (!strict_iomem_checks)
1720 return false;
1721
1722 addr = addr & PAGE_MASK;
1723
1724 read_lock(&resource_lock);
1725 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1726 /*
1727 * We can probably skip the resources without
1728 * IORESOURCE_IO attribute?
1729 */
1730 if (p->start >= addr + size)
1731 break;
1732 if (p->end < addr)
1733 continue;
1734 /*
1735 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1736 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1737 * resource is busy.
1738 */
1739 if ((p->flags & IORESOURCE_BUSY) == 0)
1740 continue;
1741 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1742 || p->flags & IORESOURCE_EXCLUSIVE) {
1743 err = true;
1744 break;
1745 }
1746 }
1747 read_unlock(&resource_lock);
1748
1749 return err;
1750}
1751
1752struct resource_entry *resource_list_create_entry(struct resource *res,
1753 size_t extra_size)
1754{
1755 struct resource_entry *entry;
1756
1757 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1758 if (entry) {
1759 INIT_LIST_HEAD(&entry->node);
1760 entry->res = res ? res : &entry->__res;
1761 }
1762
1763 return entry;
1764}
1765EXPORT_SYMBOL(resource_list_create_entry);
1766
1767void resource_list_free(struct list_head *head)
1768{
1769 struct resource_entry *entry, *tmp;
1770
1771 list_for_each_entry_safe(entry, tmp, head, node)
1772 resource_list_destroy_entry(entry);
1773}
1774EXPORT_SYMBOL(resource_list_free);
1775
1776#ifdef CONFIG_DEVICE_PRIVATE
1777static struct resource *__request_free_mem_region(struct device *dev,
1778 struct resource *base, unsigned long size, const char *name)
1779{
1780 resource_size_t end, addr;
1781 struct resource *res;
1782
1783 size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
1784 end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
1785 addr = end - size + 1UL;
1786
1787 for (; addr > size && addr >= base->start; addr -= size) {
1788 if (region_intersects(addr, size, 0, IORES_DESC_NONE) !=
1789 REGION_DISJOINT)
1790 continue;
1791
1792 if (dev)
1793 res = devm_request_mem_region(dev, addr, size, name);
1794 else
1795 res = request_mem_region(addr, size, name);
1796 if (!res)
1797 return ERR_PTR(-ENOMEM);
1798 res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
1799 return res;
1800 }
1801
1802 return ERR_PTR(-ERANGE);
1803}
1804
1805/**
1806 * devm_request_free_mem_region - find free region for device private memory
1807 *
1808 * @dev: device struct to bind the resource to
1809 * @size: size in bytes of the device memory to add
1810 * @base: resource tree to look in
1811 *
1812 * This function tries to find an empty range of physical address big enough to
1813 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1814 * memory, which in turn allocates struct pages.
1815 */
1816struct resource *devm_request_free_mem_region(struct device *dev,
1817 struct resource *base, unsigned long size)
1818{
1819 return __request_free_mem_region(dev, base, size, dev_name(dev));
1820}
1821EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
1822
1823struct resource *request_free_mem_region(struct resource *base,
1824 unsigned long size, const char *name)
1825{
1826 return __request_free_mem_region(NULL, base, size, name);
1827}
1828EXPORT_SYMBOL_GPL(request_free_mem_region);
1829
1830#endif /* CONFIG_DEVICE_PRIVATE */
1831
1832static int __init strict_iomem(char *str)
1833{
1834 if (strstr(str, "relaxed"))
1835 strict_iomem_checks = 0;
1836 if (strstr(str, "strict"))
1837 strict_iomem_checks = 1;
1838 return 1;
1839}
1840
1841static int iomem_fs_init_fs_context(struct fs_context *fc)
1842{
1843 return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM;
1844}
1845
1846static struct file_system_type iomem_fs_type = {
1847 .name = "iomem",
1848 .owner = THIS_MODULE,
1849 .init_fs_context = iomem_fs_init_fs_context,
1850 .kill_sb = kill_anon_super,
1851};
1852
1853static int __init iomem_init_inode(void)
1854{
1855 static struct vfsmount *iomem_vfs_mount;
1856 static int iomem_fs_cnt;
1857 struct inode *inode;
1858 int rc;
1859
1860 rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt);
1861 if (rc < 0) {
1862 pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc);
1863 return rc;
1864 }
1865
1866 inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb);
1867 if (IS_ERR(inode)) {
1868 rc = PTR_ERR(inode);
1869 pr_err("Cannot allocate inode for iomem: %d\n", rc);
1870 simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt);
1871 return rc;
1872 }
1873
1874 /*
1875 * Publish iomem revocation inode initialized.
1876 * Pairs with smp_load_acquire() in revoke_iomem().
1877 */
1878 smp_store_release(&iomem_inode, inode);
1879
1880 return 0;
1881}
1882
1883fs_initcall(iomem_init_inode);
1884
1885__setup("iomem=", strict_iomem);