projects/linux·blob v6.11-rc6 · 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 <linux/string.h>
31#include <linux/vmalloc.h>
32#include <asm/io.h>
33
34
35struct resource ioport_resource = {
36 .name = "PCI IO",
37 .start = 0,
38 .end = IO_SPACE_LIMIT,
39 .flags = IORESOURCE_IO,
40};
41EXPORT_SYMBOL(ioport_resource);
42
43struct resource iomem_resource = {
44 .name = "PCI mem",
45 .start = 0,
46 .end = -1,
47 .flags = IORESOURCE_MEM,
48};
49EXPORT_SYMBOL(iomem_resource);
50
51static DEFINE_RWLOCK(resource_lock);
52
53static struct resource *next_resource(struct resource *p, bool skip_children)
54{
55 if (!skip_children && p->child)
56 return p->child;
57 while (!p->sibling && p->parent)
58 p = p->parent;
59 return p->sibling;
60}
61
62#define for_each_resource(_root, _p, _skip_children) \
63 for ((_p) = (_root)->child; (_p); (_p) = next_resource(_p, _skip_children))
64
65#ifdef CONFIG_PROC_FS
66
67enum { MAX_IORES_LEVEL = 5 };
68
69static void *r_start(struct seq_file *m, loff_t *pos)
70 __acquires(resource_lock)
71{
72 struct resource *root = pde_data(file_inode(m->file));
73 struct resource *p;
74 loff_t l = *pos;
75
76 read_lock(&resource_lock);
77 for_each_resource(root, p, false) {
78 if (l-- == 0)
79 break;
80 }
81
82 return p;
83}
84
85static void *r_next(struct seq_file *m, void *v, loff_t *pos)
86{
87 struct resource *p = v;
88
89 (*pos)++;
90
91 return (void *)next_resource(p, false);
92}
93
94static void r_stop(struct seq_file *m, void *v)
95 __releases(resource_lock)
96{
97 read_unlock(&resource_lock);
98}
99
100static int r_show(struct seq_file *m, void *v)
101{
102 struct resource *root = pde_data(file_inode(m->file));
103 struct resource *r = v, *p;
104 unsigned long long start, end;
105 int width = root->end < 0x10000 ? 4 : 8;
106 int depth;
107
108 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
109 if (p->parent == root)
110 break;
111
112 if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
113 start = r->start;
114 end = r->end;
115 } else {
116 start = end = 0;
117 }
118
119 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
120 depth * 2, "",
121 width, start,
122 width, end,
123 r->name ? r->name : "<BAD>");
124 return 0;
125}
126
127static const struct seq_operations resource_op = {
128 .start = r_start,
129 .next = r_next,
130 .stop = r_stop,
131 .show = r_show,
132};
133
134static int __init ioresources_init(void)
135{
136 proc_create_seq_data("ioports", 0, NULL, &resource_op,
137 &ioport_resource);
138 proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource);
139 return 0;
140}
141__initcall(ioresources_init);
142
143#endif /* CONFIG_PROC_FS */
144
145static void free_resource(struct resource *res)
146{
147 /**
148 * If the resource was allocated using memblock early during boot
149 * we'll leak it here: we can only return full pages back to the
150 * buddy and trying to be smart and reusing them eventually in
151 * alloc_resource() overcomplicates resource handling.
152 */
153 if (res && PageSlab(virt_to_head_page(res)))
154 kfree(res);
155}
156
157static struct resource *alloc_resource(gfp_t flags)
158{
159 return kzalloc(sizeof(struct resource), flags);
160}
161
162/* Return the conflict entry if you can't request it */
163static struct resource * __request_resource(struct resource *root, struct resource *new)
164{
165 resource_size_t start = new->start;
166 resource_size_t end = new->end;
167 struct resource *tmp, **p;
168
169 if (end < start)
170 return root;
171 if (start < root->start)
172 return root;
173 if (end > root->end)
174 return root;
175 p = &root->child;
176 for (;;) {
177 tmp = *p;
178 if (!tmp || tmp->start > end) {
179 new->sibling = tmp;
180 *p = new;
181 new->parent = root;
182 return NULL;
183 }
184 p = &tmp->sibling;
185 if (tmp->end < start)
186 continue;
187 return tmp;
188 }
189}
190
191static int __release_resource(struct resource *old, bool release_child)
192{
193 struct resource *tmp, **p, *chd;
194
195 p = &old->parent->child;
196 for (;;) {
197 tmp = *p;
198 if (!tmp)
199 break;
200 if (tmp == old) {
201 if (release_child || !(tmp->child)) {
202 *p = tmp->sibling;
203 } else {
204 for (chd = tmp->child;; chd = chd->sibling) {
205 chd->parent = tmp->parent;
206 if (!(chd->sibling))
207 break;
208 }
209 *p = tmp->child;
210 chd->sibling = tmp->sibling;
211 }
212 old->parent = NULL;
213 return 0;
214 }
215 p = &tmp->sibling;
216 }
217 return -EINVAL;
218}
219
220static void __release_child_resources(struct resource *r)
221{
222 struct resource *tmp, *p;
223 resource_size_t size;
224
225 p = r->child;
226 r->child = NULL;
227 while (p) {
228 tmp = p;
229 p = p->sibling;
230
231 tmp->parent = NULL;
232 tmp->sibling = NULL;
233 __release_child_resources(tmp);
234
235 printk(KERN_DEBUG "release child resource %pR\n", tmp);
236 /* need to restore size, and keep flags */
237 size = resource_size(tmp);
238 tmp->start = 0;
239 tmp->end = size - 1;
240 }
241}
242
243void release_child_resources(struct resource *r)
244{
245 write_lock(&resource_lock);
246 __release_child_resources(r);
247 write_unlock(&resource_lock);
248}
249
250/**
251 * request_resource_conflict - request and reserve an I/O or memory resource
252 * @root: root resource descriptor
253 * @new: resource descriptor desired by caller
254 *
255 * Returns 0 for success, conflict resource on error.
256 */
257struct resource *request_resource_conflict(struct resource *root, struct resource *new)
258{
259 struct resource *conflict;
260
261 write_lock(&resource_lock);
262 conflict = __request_resource(root, new);
263 write_unlock(&resource_lock);
264 return conflict;
265}
266
267/**
268 * request_resource - request and reserve an I/O or memory resource
269 * @root: root resource descriptor
270 * @new: resource descriptor desired by caller
271 *
272 * Returns 0 for success, negative error code on error.
273 */
274int request_resource(struct resource *root, struct resource *new)
275{
276 struct resource *conflict;
277
278 conflict = request_resource_conflict(root, new);
279 return conflict ? -EBUSY : 0;
280}
281
282EXPORT_SYMBOL(request_resource);
283
284/**
285 * release_resource - release a previously reserved resource
286 * @old: resource pointer
287 */
288int release_resource(struct resource *old)
289{
290 int retval;
291
292 write_lock(&resource_lock);
293 retval = __release_resource(old, true);
294 write_unlock(&resource_lock);
295 return retval;
296}
297
298EXPORT_SYMBOL(release_resource);
299
300/**
301 * find_next_iomem_res - Finds the lowest iomem resource that covers part of
302 * [@start..@end].
303 *
304 * If a resource is found, returns 0 and @*res is overwritten with the part
305 * of the resource that's within [@start..@end]; if none is found, returns
306 * -ENODEV. Returns -EINVAL for invalid parameters.
307 *
308 * @start: start address of the resource searched for
309 * @end: end address of same resource
310 * @flags: flags which the resource must have
311 * @desc: descriptor the resource must have
312 * @res: return ptr, if resource found
313 *
314 * The caller must specify @start, @end, @flags, and @desc
315 * (which may be IORES_DESC_NONE).
316 */
317static int find_next_iomem_res(resource_size_t start, resource_size_t end,
318 unsigned long flags, unsigned long desc,
319 struct resource *res)
320{
321 struct resource *p;
322
323 if (!res)
324 return -EINVAL;
325
326 if (start >= end)
327 return -EINVAL;
328
329 read_lock(&resource_lock);
330
331 for_each_resource(&iomem_resource, p, false) {
332 /* If we passed the resource we are looking for, stop */
333 if (p->start > end) {
334 p = NULL;
335 break;
336 }
337
338 /* Skip until we find a range that matches what we look for */
339 if (p->end < start)
340 continue;
341
342 if ((p->flags & flags) != flags)
343 continue;
344 if ((desc != IORES_DESC_NONE) && (desc != p->desc))
345 continue;
346
347 /* Found a match, break */
348 break;
349 }
350
351 if (p) {
352 /* copy data */
353 *res = (struct resource) {
354 .start = max(start, p->start),
355 .end = min(end, p->end),
356 .flags = p->flags,
357 .desc = p->desc,
358 .parent = p->parent,
359 };
360 }
361
362 read_unlock(&resource_lock);
363 return p ? 0 : -ENODEV;
364}
365
366static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
367 unsigned long flags, unsigned long desc,
368 void *arg,
369 int (*func)(struct resource *, void *))
370{
371 struct resource res;
372 int ret = -EINVAL;
373
374 while (start < end &&
375 !find_next_iomem_res(start, end, flags, desc, &res)) {
376 ret = (*func)(&res, arg);
377 if (ret)
378 break;
379
380 start = res.end + 1;
381 }
382
383 return ret;
384}
385
386/**
387 * walk_iomem_res_desc - Walks through iomem resources and calls func()
388 * with matching resource ranges.
389 * *
390 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
391 * @flags: I/O resource flags
392 * @start: start addr
393 * @end: end addr
394 * @arg: function argument for the callback @func
395 * @func: callback function that is called for each qualifying resource area
396 *
397 * All the memory ranges which overlap start,end and also match flags and
398 * desc are valid candidates.
399 *
400 * NOTE: For a new descriptor search, define a new IORES_DESC in
401 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
402 */
403int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
404 u64 end, void *arg, int (*func)(struct resource *, void *))
405{
406 return __walk_iomem_res_desc(start, end, flags, desc, arg, func);
407}
408EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
409
410/*
411 * This function calls the @func callback against all memory ranges of type
412 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
413 * Now, this function is only for System RAM, it deals with full ranges and
414 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
415 * ranges.
416 */
417int walk_system_ram_res(u64 start, u64 end, void *arg,
418 int (*func)(struct resource *, void *))
419{
420 unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
421
422 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
423 func);
424}
425
426/*
427 * This function, being a variant of walk_system_ram_res(), calls the @func
428 * callback against all memory ranges of type System RAM which are marked as
429 * IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY in reversed order, i.e., from
430 * higher to lower.
431 */
432int walk_system_ram_res_rev(u64 start, u64 end, void *arg,
433 int (*func)(struct resource *, void *))
434{
435 struct resource res, *rams;
436 int rams_size = 16, i;
437 unsigned long flags;
438 int ret = -1;
439
440 /* create a list */
441 rams = kvcalloc(rams_size, sizeof(struct resource), GFP_KERNEL);
442 if (!rams)
443 return ret;
444
445 flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
446 i = 0;
447 while ((start < end) &&
448 (!find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res))) {
449 if (i >= rams_size) {
450 /* re-alloc */
451 struct resource *rams_new;
452
453 rams_new = kvrealloc(rams, rams_size * sizeof(struct resource),
454 (rams_size + 16) * sizeof(struct resource),
455 GFP_KERNEL);
456 if (!rams_new)
457 goto out;
458
459 rams = rams_new;
460 rams_size += 16;
461 }
462
463 rams[i].start = res.start;
464 rams[i++].end = res.end;
465
466 start = res.end + 1;
467 }
468
469 /* go reverse */
470 for (i--; i >= 0; i--) {
471 ret = (*func)(&rams[i], arg);
472 if (ret)
473 break;
474 }
475
476out:
477 kvfree(rams);
478 return ret;
479}
480
481/*
482 * This function calls the @func callback against all memory ranges, which
483 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
484 */
485int walk_mem_res(u64 start, u64 end, void *arg,
486 int (*func)(struct resource *, void *))
487{
488 unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
489
490 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
491 func);
492}
493
494/*
495 * This function calls the @func callback against all memory ranges of type
496 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
497 * It is to be used only for System RAM.
498 */
499int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
500 void *arg, int (*func)(unsigned long, unsigned long, void *))
501{
502 resource_size_t start, end;
503 unsigned long flags;
504 struct resource res;
505 unsigned long pfn, end_pfn;
506 int ret = -EINVAL;
507
508 start = (u64) start_pfn << PAGE_SHIFT;
509 end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
510 flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
511 while (start < end &&
512 !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res)) {
513 pfn = PFN_UP(res.start);
514 end_pfn = PFN_DOWN(res.end + 1);
515 if (end_pfn > pfn)
516 ret = (*func)(pfn, end_pfn - pfn, arg);
517 if (ret)
518 break;
519 start = res.end + 1;
520 }
521 return ret;
522}
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
539static int __region_intersects(struct resource *parent, resource_size_t start,
540 size_t size, unsigned long flags,
541 unsigned long desc)
542{
543 struct resource res;
544 int type = 0; int other = 0;
545 struct resource *p;
546
547 res.start = start;
548 res.end = start + size - 1;
549
550 for (p = parent->child; p ; p = p->sibling) {
551 bool is_type = (((p->flags & flags) == flags) &&
552 ((desc == IORES_DESC_NONE) ||
553 (desc == p->desc)));
554
555 if (resource_overlaps(p, &res))
556 is_type ? type++ : other++;
557 }
558
559 if (type == 0)
560 return REGION_DISJOINT;
561
562 if (other == 0)
563 return REGION_INTERSECTS;
564
565 return REGION_MIXED;
566}
567
568/**
569 * region_intersects() - determine intersection of region with known resources
570 * @start: region start address
571 * @size: size of region
572 * @flags: flags of resource (in iomem_resource)
573 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
574 *
575 * Check if the specified region partially overlaps or fully eclipses a
576 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
577 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
578 * return REGION_MIXED if the region overlaps @flags/@desc and another
579 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
580 * and no other defined resource. Note that REGION_INTERSECTS is also
581 * returned in the case when the specified region overlaps RAM and undefined
582 * memory holes.
583 *
584 * region_intersect() is used by memory remapping functions to ensure
585 * the user is not remapping RAM and is a vast speed up over walking
586 * through the resource table page by page.
587 */
588int region_intersects(resource_size_t start, size_t size, unsigned long flags,
589 unsigned long desc)
590{
591 int ret;
592
593 read_lock(&resource_lock);
594 ret = __region_intersects(&iomem_resource, start, size, flags, desc);
595 read_unlock(&resource_lock);
596
597 return ret;
598}
599EXPORT_SYMBOL_GPL(region_intersects);
600
601void __weak arch_remove_reservations(struct resource *avail)
602{
603}
604
605static void resource_clip(struct resource *res, resource_size_t min,
606 resource_size_t max)
607{
608 if (res->start < min)
609 res->start = min;
610 if (res->end > max)
611 res->end = max;
612}
613
614/*
615 * Find empty space in the resource tree with the given range and
616 * alignment constraints
617 */
618static int __find_resource_space(struct resource *root, struct resource *old,
619 struct resource *new, resource_size_t size,
620 struct resource_constraint *constraint)
621{
622 struct resource *this = root->child;
623 struct resource tmp = *new, avail, alloc;
624 resource_alignf alignf = constraint->alignf;
625
626 tmp.start = root->start;
627 /*
628 * Skip past an allocated resource that starts at 0, since the assignment
629 * of this->start - 1 to tmp->end below would cause an underflow.
630 */
631 if (this && this->start == root->start) {
632 tmp.start = (this == old) ? old->start : this->end + 1;
633 this = this->sibling;
634 }
635 for(;;) {
636 if (this)
637 tmp.end = (this == old) ? this->end : this->start - 1;
638 else
639 tmp.end = root->end;
640
641 if (tmp.end < tmp.start)
642 goto next;
643
644 resource_clip(&tmp, constraint->min, constraint->max);
645 arch_remove_reservations(&tmp);
646
647 /* Check for overflow after ALIGN() */
648 avail.start = ALIGN(tmp.start, constraint->align);
649 avail.end = tmp.end;
650 avail.flags = new->flags & ~IORESOURCE_UNSET;
651 if (avail.start >= tmp.start) {
652 alloc.flags = avail.flags;
653 if (alignf) {
654 alloc.start = alignf(constraint->alignf_data,
655 &avail, size, constraint->align);
656 } else {
657 alloc.start = avail.start;
658 }
659 alloc.end = alloc.start + size - 1;
660 if (alloc.start <= alloc.end &&
661 resource_contains(&avail, &alloc)) {
662 new->start = alloc.start;
663 new->end = alloc.end;
664 return 0;
665 }
666 }
667
668next: if (!this || this->end == root->end)
669 break;
670
671 if (this != old)
672 tmp.start = this->end + 1;
673 this = this->sibling;
674 }
675 return -EBUSY;
676}
677
678/**
679 * find_resource_space - Find empty space in the resource tree
680 * @root: Root resource descriptor
681 * @new: Resource descriptor awaiting an empty resource space
682 * @size: The minimum size of the empty space
683 * @constraint: The range and alignment constraints to be met
684 *
685 * Finds an empty space under @root in the resource tree satisfying range and
686 * alignment @constraints.
687 *
688 * Return:
689 * * %0 - if successful, @new members start, end, and flags are altered.
690 * * %-EBUSY - if no empty space was found.
691 */
692int find_resource_space(struct resource *root, struct resource *new,
693 resource_size_t size,
694 struct resource_constraint *constraint)
695{
696 return __find_resource_space(root, NULL, new, size, constraint);
697}
698EXPORT_SYMBOL_GPL(find_resource_space);
699
700/**
701 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
702 * The resource will be relocated if the new size cannot be reallocated in the
703 * current location.
704 *
705 * @root: root resource descriptor
706 * @old: resource descriptor desired by caller
707 * @newsize: new size of the resource descriptor
708 * @constraint: the size and alignment constraints to be met.
709 */
710static int reallocate_resource(struct resource *root, struct resource *old,
711 resource_size_t newsize,
712 struct resource_constraint *constraint)
713{
714 int err=0;
715 struct resource new = *old;
716 struct resource *conflict;
717
718 write_lock(&resource_lock);
719
720 if ((err = __find_resource_space(root, old, &new, newsize, constraint)))
721 goto out;
722
723 if (resource_contains(&new, old)) {
724 old->start = new.start;
725 old->end = new.end;
726 goto out;
727 }
728
729 if (old->child) {
730 err = -EBUSY;
731 goto out;
732 }
733
734 if (resource_contains(old, &new)) {
735 old->start = new.start;
736 old->end = new.end;
737 } else {
738 __release_resource(old, true);
739 *old = new;
740 conflict = __request_resource(root, old);
741 BUG_ON(conflict);
742 }
743out:
744 write_unlock(&resource_lock);
745 return err;
746}
747
748
749/**
750 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
751 * The resource will be reallocated with a new size if it was already allocated
752 * @root: root resource descriptor
753 * @new: resource descriptor desired by caller
754 * @size: requested resource region size
755 * @min: minimum boundary to allocate
756 * @max: maximum boundary to allocate
757 * @align: alignment requested, in bytes
758 * @alignf: alignment function, optional, called if not NULL
759 * @alignf_data: arbitrary data to pass to the @alignf function
760 */
761int allocate_resource(struct resource *root, struct resource *new,
762 resource_size_t size, resource_size_t min,
763 resource_size_t max, resource_size_t align,
764 resource_alignf alignf,
765 void *alignf_data)
766{
767 int err;
768 struct resource_constraint constraint;
769
770 constraint.min = min;
771 constraint.max = max;
772 constraint.align = align;
773 constraint.alignf = alignf;
774 constraint.alignf_data = alignf_data;
775
776 if ( new->parent ) {
777 /* resource is already allocated, try reallocating with
778 the new constraints */
779 return reallocate_resource(root, new, size, &constraint);
780 }
781
782 write_lock(&resource_lock);
783 err = find_resource_space(root, new, size, &constraint);
784 if (err >= 0 && __request_resource(root, new))
785 err = -EBUSY;
786 write_unlock(&resource_lock);
787 return err;
788}
789
790EXPORT_SYMBOL(allocate_resource);
791
792/**
793 * lookup_resource - find an existing resource by a resource start address
794 * @root: root resource descriptor
795 * @start: resource start address
796 *
797 * Returns a pointer to the resource if found, NULL otherwise
798 */
799struct resource *lookup_resource(struct resource *root, resource_size_t start)
800{
801 struct resource *res;
802
803 read_lock(&resource_lock);
804 for (res = root->child; res; res = res->sibling) {
805 if (res->start == start)
806 break;
807 }
808 read_unlock(&resource_lock);
809
810 return res;
811}
812
813/*
814 * Insert a resource into the resource tree. If successful, return NULL,
815 * otherwise return the conflicting resource (compare to __request_resource())
816 */
817static struct resource * __insert_resource(struct resource *parent, struct resource *new)
818{
819 struct resource *first, *next;
820
821 for (;; parent = first) {
822 first = __request_resource(parent, new);
823 if (!first)
824 return first;
825
826 if (first == parent)
827 return first;
828 if (WARN_ON(first == new)) /* duplicated insertion */
829 return first;
830
831 if ((first->start > new->start) || (first->end < new->end))
832 break;
833 if ((first->start == new->start) && (first->end == new->end))
834 break;
835 }
836
837 for (next = first; ; next = next->sibling) {
838 /* Partial overlap? Bad, and unfixable */
839 if (next->start < new->start || next->end > new->end)
840 return next;
841 if (!next->sibling)
842 break;
843 if (next->sibling->start > new->end)
844 break;
845 }
846
847 new->parent = parent;
848 new->sibling = next->sibling;
849 new->child = first;
850
851 next->sibling = NULL;
852 for (next = first; next; next = next->sibling)
853 next->parent = new;
854
855 if (parent->child == first) {
856 parent->child = new;
857 } else {
858 next = parent->child;
859 while (next->sibling != first)
860 next = next->sibling;
861 next->sibling = new;
862 }
863 return NULL;
864}
865
866/**
867 * insert_resource_conflict - Inserts resource in the resource tree
868 * @parent: parent of the new resource
869 * @new: new resource to insert
870 *
871 * Returns 0 on success, conflict resource if the resource can't be inserted.
872 *
873 * This function is equivalent to request_resource_conflict when no conflict
874 * happens. If a conflict happens, and the conflicting resources
875 * entirely fit within the range of the new resource, then the new
876 * resource is inserted and the conflicting resources become children of
877 * the new resource.
878 *
879 * This function is intended for producers of resources, such as FW modules
880 * and bus drivers.
881 */
882struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
883{
884 struct resource *conflict;
885
886 write_lock(&resource_lock);
887 conflict = __insert_resource(parent, new);
888 write_unlock(&resource_lock);
889 return conflict;
890}
891
892/**
893 * insert_resource - Inserts a resource in the resource tree
894 * @parent: parent of the new resource
895 * @new: new resource to insert
896 *
897 * Returns 0 on success, -EBUSY if the resource can't be inserted.
898 *
899 * This function is intended for producers of resources, such as FW modules
900 * and bus drivers.
901 */
902int insert_resource(struct resource *parent, struct resource *new)
903{
904 struct resource *conflict;
905
906 conflict = insert_resource_conflict(parent, new);
907 return conflict ? -EBUSY : 0;
908}
909EXPORT_SYMBOL_GPL(insert_resource);
910
911/**
912 * insert_resource_expand_to_fit - Insert a resource into the resource tree
913 * @root: root resource descriptor
914 * @new: new resource to insert
915 *
916 * Insert a resource into the resource tree, possibly expanding it in order
917 * to make it encompass any conflicting resources.
918 */
919void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
920{
921 if (new->parent)
922 return;
923
924 write_lock(&resource_lock);
925 for (;;) {
926 struct resource *conflict;
927
928 conflict = __insert_resource(root, new);
929 if (!conflict)
930 break;
931 if (conflict == root)
932 break;
933
934 /* Ok, expand resource to cover the conflict, then try again .. */
935 if (conflict->start < new->start)
936 new->start = conflict->start;
937 if (conflict->end > new->end)
938 new->end = conflict->end;
939
940 pr_info("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
941 }
942 write_unlock(&resource_lock);
943}
944/*
945 * Not for general consumption, only early boot memory map parsing, PCI
946 * resource discovery, and late discovery of CXL resources are expected
947 * to use this interface. The former are built-in and only the latter,
948 * CXL, is a module.
949 */
950EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit, CXL);
951
952/**
953 * remove_resource - Remove a resource in the resource tree
954 * @old: resource to remove
955 *
956 * Returns 0 on success, -EINVAL if the resource is not valid.
957 *
958 * This function removes a resource previously inserted by insert_resource()
959 * or insert_resource_conflict(), and moves the children (if any) up to
960 * where they were before. insert_resource() and insert_resource_conflict()
961 * insert a new resource, and move any conflicting resources down to the
962 * children of the new resource.
963 *
964 * insert_resource(), insert_resource_conflict() and remove_resource() are
965 * intended for producers of resources, such as FW modules and bus drivers.
966 */
967int remove_resource(struct resource *old)
968{
969 int retval;
970
971 write_lock(&resource_lock);
972 retval = __release_resource(old, false);
973 write_unlock(&resource_lock);
974 return retval;
975}
976EXPORT_SYMBOL_GPL(remove_resource);
977
978static int __adjust_resource(struct resource *res, resource_size_t start,
979 resource_size_t size)
980{
981 struct resource *tmp, *parent = res->parent;
982 resource_size_t end = start + size - 1;
983 int result = -EBUSY;
984
985 if (!parent)
986 goto skip;
987
988 if ((start < parent->start) || (end > parent->end))
989 goto out;
990
991 if (res->sibling && (res->sibling->start <= end))
992 goto out;
993
994 tmp = parent->child;
995 if (tmp != res) {
996 while (tmp->sibling != res)
997 tmp = tmp->sibling;
998 if (start <= tmp->end)
999 goto out;
1000 }
1001
1002skip:
1003 for (tmp = res->child; tmp; tmp = tmp->sibling)
1004 if ((tmp->start < start) || (tmp->end > end))
1005 goto out;
1006
1007 res->start = start;
1008 res->end = end;
1009 result = 0;
1010
1011 out:
1012 return result;
1013}
1014
1015/**
1016 * adjust_resource - modify a resource's start and size
1017 * @res: resource to modify
1018 * @start: new start value
1019 * @size: new size
1020 *
1021 * Given an existing resource, change its start and size to match the
1022 * arguments. Returns 0 on success, -EBUSY if it can't fit.
1023 * Existing children of the resource are assumed to be immutable.
1024 */
1025int adjust_resource(struct resource *res, resource_size_t start,
1026 resource_size_t size)
1027{
1028 int result;
1029
1030 write_lock(&resource_lock);
1031 result = __adjust_resource(res, start, size);
1032 write_unlock(&resource_lock);
1033 return result;
1034}
1035EXPORT_SYMBOL(adjust_resource);
1036
1037static void __init
1038__reserve_region_with_split(struct resource *root, resource_size_t start,
1039 resource_size_t end, const char *name)
1040{
1041 struct resource *parent = root;
1042 struct resource *conflict;
1043 struct resource *res = alloc_resource(GFP_ATOMIC);
1044 struct resource *next_res = NULL;
1045 int type = resource_type(root);
1046
1047 if (!res)
1048 return;
1049
1050 res->name = name;
1051 res->start = start;
1052 res->end = end;
1053 res->flags = type | IORESOURCE_BUSY;
1054 res->desc = IORES_DESC_NONE;
1055
1056 while (1) {
1057
1058 conflict = __request_resource(parent, res);
1059 if (!conflict) {
1060 if (!next_res)
1061 break;
1062 res = next_res;
1063 next_res = NULL;
1064 continue;
1065 }
1066
1067 /* conflict covered whole area */
1068 if (conflict->start <= res->start &&
1069 conflict->end >= res->end) {
1070 free_resource(res);
1071 WARN_ON(next_res);
1072 break;
1073 }
1074
1075 /* failed, split and try again */
1076 if (conflict->start > res->start) {
1077 end = res->end;
1078 res->end = conflict->start - 1;
1079 if (conflict->end < end) {
1080 next_res = alloc_resource(GFP_ATOMIC);
1081 if (!next_res) {
1082 free_resource(res);
1083 break;
1084 }
1085 next_res->name = name;
1086 next_res->start = conflict->end + 1;
1087 next_res->end = end;
1088 next_res->flags = type | IORESOURCE_BUSY;
1089 next_res->desc = IORES_DESC_NONE;
1090 }
1091 } else {
1092 res->start = conflict->end + 1;
1093 }
1094 }
1095
1096}
1097
1098void __init
1099reserve_region_with_split(struct resource *root, resource_size_t start,
1100 resource_size_t end, const char *name)
1101{
1102 int abort = 0;
1103
1104 write_lock(&resource_lock);
1105 if (root->start > start || root->end < end) {
1106 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1107 (unsigned long long)start, (unsigned long long)end,
1108 root);
1109 if (start > root->end || end < root->start)
1110 abort = 1;
1111 else {
1112 if (end > root->end)
1113 end = root->end;
1114 if (start < root->start)
1115 start = root->start;
1116 pr_err("fixing request to [0x%llx-0x%llx]\n",
1117 (unsigned long long)start,
1118 (unsigned long long)end);
1119 }
1120 dump_stack();
1121 }
1122 if (!abort)
1123 __reserve_region_with_split(root, start, end, name);
1124 write_unlock(&resource_lock);
1125}
1126
1127/**
1128 * resource_alignment - calculate resource's alignment
1129 * @res: resource pointer
1130 *
1131 * Returns alignment on success, 0 (invalid alignment) on failure.
1132 */
1133resource_size_t resource_alignment(struct resource *res)
1134{
1135 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1136 case IORESOURCE_SIZEALIGN:
1137 return resource_size(res);
1138 case IORESOURCE_STARTALIGN:
1139 return res->start;
1140 default:
1141 return 0;
1142 }
1143}
1144
1145/*
1146 * This is compatibility stuff for IO resources.
1147 *
1148 * Note how this, unlike the above, knows about
1149 * the IO flag meanings (busy etc).
1150 *
1151 * request_region creates a new busy region.
1152 *
1153 * release_region releases a matching busy region.
1154 */
1155
1156static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1157
1158static struct inode *iomem_inode;
1159
1160#ifdef CONFIG_IO_STRICT_DEVMEM
1161static void revoke_iomem(struct resource *res)
1162{
1163 /* pairs with smp_store_release() in iomem_init_inode() */
1164 struct inode *inode = smp_load_acquire(&iomem_inode);
1165
1166 /*
1167 * Check that the initialization has completed. Losing the race
1168 * is ok because it means drivers are claiming resources before
1169 * the fs_initcall level of init and prevent iomem_get_mapping users
1170 * from establishing mappings.
1171 */
1172 if (!inode)
1173 return;
1174
1175 /*
1176 * The expectation is that the driver has successfully marked
1177 * the resource busy by this point, so devmem_is_allowed()
1178 * should start returning false, however for performance this
1179 * does not iterate the entire resource range.
1180 */
1181 if (devmem_is_allowed(PHYS_PFN(res->start)) &&
1182 devmem_is_allowed(PHYS_PFN(res->end))) {
1183 /*
1184 * *cringe* iomem=relaxed says "go ahead, what's the
1185 * worst that can happen?"
1186 */
1187 return;
1188 }
1189
1190 unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1);
1191}
1192#else
1193static void revoke_iomem(struct resource *res) {}
1194#endif
1195
1196struct address_space *iomem_get_mapping(void)
1197{
1198 /*
1199 * This function is only called from file open paths, hence guaranteed
1200 * that fs_initcalls have completed and no need to check for NULL. But
1201 * since revoke_iomem can be called before the initcall we still need
1202 * the barrier to appease checkers.
1203 */
1204 return smp_load_acquire(&iomem_inode)->i_mapping;
1205}
1206
1207static int __request_region_locked(struct resource *res, struct resource *parent,
1208 resource_size_t start, resource_size_t n,
1209 const char *name, int flags)
1210{
1211 DECLARE_WAITQUEUE(wait, current);
1212
1213 res->name = name;
1214 res->start = start;
1215 res->end = start + n - 1;
1216
1217 for (;;) {
1218 struct resource *conflict;
1219
1220 res->flags = resource_type(parent) | resource_ext_type(parent);
1221 res->flags |= IORESOURCE_BUSY | flags;
1222 res->desc = parent->desc;
1223
1224 conflict = __request_resource(parent, res);
1225 if (!conflict)
1226 break;
1227 /*
1228 * mm/hmm.c reserves physical addresses which then
1229 * become unavailable to other users. Conflicts are
1230 * not expected. Warn to aid debugging if encountered.
1231 */
1232 if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1233 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1234 conflict->name, conflict, res);
1235 }
1236 if (conflict != parent) {
1237 if (!(conflict->flags & IORESOURCE_BUSY)) {
1238 parent = conflict;
1239 continue;
1240 }
1241 }
1242 if (conflict->flags & flags & IORESOURCE_MUXED) {
1243 add_wait_queue(&muxed_resource_wait, &wait);
1244 write_unlock(&resource_lock);
1245 set_current_state(TASK_UNINTERRUPTIBLE);
1246 schedule();
1247 remove_wait_queue(&muxed_resource_wait, &wait);
1248 write_lock(&resource_lock);
1249 continue;
1250 }
1251 /* Uhhuh, that didn't work out.. */
1252 return -EBUSY;
1253 }
1254
1255 return 0;
1256}
1257
1258/**
1259 * __request_region - create a new busy resource region
1260 * @parent: parent resource descriptor
1261 * @start: resource start address
1262 * @n: resource region size
1263 * @name: reserving caller's ID string
1264 * @flags: IO resource flags
1265 */
1266struct resource *__request_region(struct resource *parent,
1267 resource_size_t start, resource_size_t n,
1268 const char *name, int flags)
1269{
1270 struct resource *res = alloc_resource(GFP_KERNEL);
1271 int ret;
1272
1273 if (!res)
1274 return NULL;
1275
1276 write_lock(&resource_lock);
1277 ret = __request_region_locked(res, parent, start, n, name, flags);
1278 write_unlock(&resource_lock);
1279
1280 if (ret) {
1281 free_resource(res);
1282 return NULL;
1283 }
1284
1285 if (parent == &iomem_resource)
1286 revoke_iomem(res);
1287
1288 return res;
1289}
1290EXPORT_SYMBOL(__request_region);
1291
1292/**
1293 * __release_region - release a previously reserved resource region
1294 * @parent: parent resource descriptor
1295 * @start: resource start address
1296 * @n: resource region size
1297 *
1298 * The described resource region must match a currently busy region.
1299 */
1300void __release_region(struct resource *parent, resource_size_t start,
1301 resource_size_t n)
1302{
1303 struct resource **p;
1304 resource_size_t end;
1305
1306 p = &parent->child;
1307 end = start + n - 1;
1308
1309 write_lock(&resource_lock);
1310
1311 for (;;) {
1312 struct resource *res = *p;
1313
1314 if (!res)
1315 break;
1316 if (res->start <= start && res->end >= end) {
1317 if (!(res->flags & IORESOURCE_BUSY)) {
1318 p = &res->child;
1319 continue;
1320 }
1321 if (res->start != start || res->end != end)
1322 break;
1323 *p = res->sibling;
1324 write_unlock(&resource_lock);
1325 if (res->flags & IORESOURCE_MUXED)
1326 wake_up(&muxed_resource_wait);
1327 free_resource(res);
1328 return;
1329 }
1330 p = &res->sibling;
1331 }
1332
1333 write_unlock(&resource_lock);
1334
1335 pr_warn("Trying to free nonexistent resource <%pa-%pa>\n", &start, &end);
1336}
1337EXPORT_SYMBOL(__release_region);
1338
1339#ifdef CONFIG_MEMORY_HOTREMOVE
1340/**
1341 * release_mem_region_adjustable - release a previously reserved memory region
1342 * @start: resource start address
1343 * @size: resource region size
1344 *
1345 * This interface is intended for memory hot-delete. The requested region
1346 * is released from a currently busy memory resource. The requested region
1347 * must either match exactly or fit into a single busy resource entry. In
1348 * the latter case, the remaining resource is adjusted accordingly.
1349 * Existing children of the busy memory resource must be immutable in the
1350 * request.
1351 *
1352 * Note:
1353 * - Additional release conditions, such as overlapping region, can be
1354 * supported after they are confirmed as valid cases.
1355 * - When a busy memory resource gets split into two entries, the code
1356 * assumes that all children remain in the lower address entry for
1357 * simplicity. Enhance this logic when necessary.
1358 */
1359void release_mem_region_adjustable(resource_size_t start, resource_size_t size)
1360{
1361 struct resource *parent = &iomem_resource;
1362 struct resource *new_res = NULL;
1363 bool alloc_nofail = false;
1364 struct resource **p;
1365 struct resource *res;
1366 resource_size_t end;
1367
1368 end = start + size - 1;
1369 if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
1370 return;
1371
1372 /*
1373 * We free up quite a lot of memory on memory hotunplug (esp., memap),
1374 * just before releasing the region. This is highly unlikely to
1375 * fail - let's play save and make it never fail as the caller cannot
1376 * perform any error handling (e.g., trying to re-add memory will fail
1377 * similarly).
1378 */
1379retry:
1380 new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
1381
1382 p = &parent->child;
1383 write_lock(&resource_lock);
1384
1385 while ((res = *p)) {
1386 if (res->start >= end)
1387 break;
1388
1389 /* look for the next resource if it does not fit into */
1390 if (res->start > start || res->end < end) {
1391 p = &res->sibling;
1392 continue;
1393 }
1394
1395 if (!(res->flags & IORESOURCE_MEM))
1396 break;
1397
1398 if (!(res->flags & IORESOURCE_BUSY)) {
1399 p = &res->child;
1400 continue;
1401 }
1402
1403 /* found the target resource; let's adjust accordingly */
1404 if (res->start == start && res->end == end) {
1405 /* free the whole entry */
1406 *p = res->sibling;
1407 free_resource(res);
1408 } else if (res->start == start && res->end != end) {
1409 /* adjust the start */
1410 WARN_ON_ONCE(__adjust_resource(res, end + 1,
1411 res->end - end));
1412 } else if (res->start != start && res->end == end) {
1413 /* adjust the end */
1414 WARN_ON_ONCE(__adjust_resource(res, res->start,
1415 start - res->start));
1416 } else {
1417 /* split into two entries - we need a new resource */
1418 if (!new_res) {
1419 new_res = alloc_resource(GFP_ATOMIC);
1420 if (!new_res) {
1421 alloc_nofail = true;
1422 write_unlock(&resource_lock);
1423 goto retry;
1424 }
1425 }
1426 new_res->name = res->name;
1427 new_res->start = end + 1;
1428 new_res->end = res->end;
1429 new_res->flags = res->flags;
1430 new_res->desc = res->desc;
1431 new_res->parent = res->parent;
1432 new_res->sibling = res->sibling;
1433 new_res->child = NULL;
1434
1435 if (WARN_ON_ONCE(__adjust_resource(res, res->start,
1436 start - res->start)))
1437 break;
1438 res->sibling = new_res;
1439 new_res = NULL;
1440 }
1441
1442 break;
1443 }
1444
1445 write_unlock(&resource_lock);
1446 free_resource(new_res);
1447}
1448#endif /* CONFIG_MEMORY_HOTREMOVE */
1449
1450#ifdef CONFIG_MEMORY_HOTPLUG
1451static bool system_ram_resources_mergeable(struct resource *r1,
1452 struct resource *r2)
1453{
1454 /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1455 return r1->flags == r2->flags && r1->end + 1 == r2->start &&
1456 r1->name == r2->name && r1->desc == r2->desc &&
1457 !r1->child && !r2->child;
1458}
1459
1460/**
1461 * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1462 * merge it with adjacent, mergeable resources
1463 * @res: resource descriptor
1464 *
1465 * This interface is intended for memory hotplug, whereby lots of contiguous
1466 * system ram resources are added (e.g., via add_memory*()) by a driver, and
1467 * the actual resource boundaries are not of interest (e.g., it might be
1468 * relevant for DIMMs). Only resources that are marked mergeable, that have the
1469 * same parent, and that don't have any children are considered. All mergeable
1470 * resources must be immutable during the request.
1471 *
1472 * Note:
1473 * - The caller has to make sure that no pointers to resources that are
1474 * marked mergeable are used anymore after this call - the resource might
1475 * be freed and the pointer might be stale!
1476 * - release_mem_region_adjustable() will split on demand on memory hotunplug
1477 */
1478void merge_system_ram_resource(struct resource *res)
1479{
1480 const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
1481 struct resource *cur;
1482
1483 if (WARN_ON_ONCE((res->flags & flags) != flags))
1484 return;
1485
1486 write_lock(&resource_lock);
1487 res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
1488
1489 /* Try to merge with next item in the list. */
1490 cur = res->sibling;
1491 if (cur && system_ram_resources_mergeable(res, cur)) {
1492 res->end = cur->end;
1493 res->sibling = cur->sibling;
1494 free_resource(cur);
1495 }
1496
1497 /* Try to merge with previous item in the list. */
1498 cur = res->parent->child;
1499 while (cur && cur->sibling != res)
1500 cur = cur->sibling;
1501 if (cur && system_ram_resources_mergeable(cur, res)) {
1502 cur->end = res->end;
1503 cur->sibling = res->sibling;
1504 free_resource(res);
1505 }
1506 write_unlock(&resource_lock);
1507}
1508#endif /* CONFIG_MEMORY_HOTPLUG */
1509
1510/*
1511 * Managed region resource
1512 */
1513static void devm_resource_release(struct device *dev, void *ptr)
1514{
1515 struct resource **r = ptr;
1516
1517 release_resource(*r);
1518}
1519
1520/**
1521 * devm_request_resource() - request and reserve an I/O or memory resource
1522 * @dev: device for which to request the resource
1523 * @root: root of the resource tree from which to request the resource
1524 * @new: descriptor of the resource to request
1525 *
1526 * This is a device-managed version of request_resource(). There is usually
1527 * no need to release resources requested by this function explicitly since
1528 * that will be taken care of when the device is unbound from its driver.
1529 * If for some reason the resource needs to be released explicitly, because
1530 * of ordering issues for example, drivers must call devm_release_resource()
1531 * rather than the regular release_resource().
1532 *
1533 * When a conflict is detected between any existing resources and the newly
1534 * requested resource, an error message will be printed.
1535 *
1536 * Returns 0 on success or a negative error code on failure.
1537 */
1538int devm_request_resource(struct device *dev, struct resource *root,
1539 struct resource *new)
1540{
1541 struct resource *conflict, **ptr;
1542
1543 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1544 if (!ptr)
1545 return -ENOMEM;
1546
1547 *ptr = new;
1548
1549 conflict = request_resource_conflict(root, new);
1550 if (conflict) {
1551 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1552 new, conflict->name, conflict);
1553 devres_free(ptr);
1554 return -EBUSY;
1555 }
1556
1557 devres_add(dev, ptr);
1558 return 0;
1559}
1560EXPORT_SYMBOL(devm_request_resource);
1561
1562static int devm_resource_match(struct device *dev, void *res, void *data)
1563{
1564 struct resource **ptr = res;
1565
1566 return *ptr == data;
1567}
1568
1569/**
1570 * devm_release_resource() - release a previously requested resource
1571 * @dev: device for which to release the resource
1572 * @new: descriptor of the resource to release
1573 *
1574 * Releases a resource previously requested using devm_request_resource().
1575 */
1576void devm_release_resource(struct device *dev, struct resource *new)
1577{
1578 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1579 new));
1580}
1581EXPORT_SYMBOL(devm_release_resource);
1582
1583struct region_devres {
1584 struct resource *parent;
1585 resource_size_t start;
1586 resource_size_t n;
1587};
1588
1589static void devm_region_release(struct device *dev, void *res)
1590{
1591 struct region_devres *this = res;
1592
1593 __release_region(this->parent, this->start, this->n);
1594}
1595
1596static int devm_region_match(struct device *dev, void *res, void *match_data)
1597{
1598 struct region_devres *this = res, *match = match_data;
1599
1600 return this->parent == match->parent &&
1601 this->start == match->start && this->n == match->n;
1602}
1603
1604struct resource *
1605__devm_request_region(struct device *dev, struct resource *parent,
1606 resource_size_t start, resource_size_t n, const char *name)
1607{
1608 struct region_devres *dr = NULL;
1609 struct resource *res;
1610
1611 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1612 GFP_KERNEL);
1613 if (!dr)
1614 return NULL;
1615
1616 dr->parent = parent;
1617 dr->start = start;
1618 dr->n = n;
1619
1620 res = __request_region(parent, start, n, name, 0);
1621 if (res)
1622 devres_add(dev, dr);
1623 else
1624 devres_free(dr);
1625
1626 return res;
1627}
1628EXPORT_SYMBOL(__devm_request_region);
1629
1630void __devm_release_region(struct device *dev, struct resource *parent,
1631 resource_size_t start, resource_size_t n)
1632{
1633 struct region_devres match_data = { parent, start, n };
1634
1635 __release_region(parent, start, n);
1636 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1637 &match_data));
1638}
1639EXPORT_SYMBOL(__devm_release_region);
1640
1641/*
1642 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1643 */
1644#define MAXRESERVE 4
1645static int __init reserve_setup(char *str)
1646{
1647 static int reserved;
1648 static struct resource reserve[MAXRESERVE];
1649
1650 for (;;) {
1651 unsigned int io_start, io_num;
1652 int x = reserved;
1653 struct resource *parent;
1654
1655 if (get_option(&str, &io_start) != 2)
1656 break;
1657 if (get_option(&str, &io_num) == 0)
1658 break;
1659 if (x < MAXRESERVE) {
1660 struct resource *res = reserve + x;
1661
1662 /*
1663 * If the region starts below 0x10000, we assume it's
1664 * I/O port space; otherwise assume it's memory.
1665 */
1666 if (io_start < 0x10000) {
1667 res->flags = IORESOURCE_IO;
1668 parent = &ioport_resource;
1669 } else {
1670 res->flags = IORESOURCE_MEM;
1671 parent = &iomem_resource;
1672 }
1673 res->name = "reserved";
1674 res->start = io_start;
1675 res->end = io_start + io_num - 1;
1676 res->flags |= IORESOURCE_BUSY;
1677 res->desc = IORES_DESC_NONE;
1678 res->child = NULL;
1679 if (request_resource(parent, res) == 0)
1680 reserved = x+1;
1681 }
1682 }
1683 return 1;
1684}
1685__setup("reserve=", reserve_setup);
1686
1687/*
1688 * Check if the requested addr and size spans more than any slot in the
1689 * iomem resource tree.
1690 */
1691int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1692{
1693 resource_size_t end = addr + size - 1;
1694 struct resource *p;
1695 int err = 0;
1696
1697 read_lock(&resource_lock);
1698 for_each_resource(&iomem_resource, p, false) {
1699 /*
1700 * We can probably skip the resources without
1701 * IORESOURCE_IO attribute?
1702 */
1703 if (p->start > end)
1704 continue;
1705 if (p->end < addr)
1706 continue;
1707 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1708 PFN_DOWN(p->end) >= PFN_DOWN(end))
1709 continue;
1710 /*
1711 * if a resource is "BUSY", it's not a hardware resource
1712 * but a driver mapping of such a resource; we don't want
1713 * to warn for those; some drivers legitimately map only
1714 * partial hardware resources. (example: vesafb)
1715 */
1716 if (p->flags & IORESOURCE_BUSY)
1717 continue;
1718
1719 pr_warn("resource sanity check: requesting [mem %pa-%pa], which spans more than %s %pR\n",
1720 &addr, &end, p->name, p);
1721 err = -1;
1722 break;
1723 }
1724 read_unlock(&resource_lock);
1725
1726 return err;
1727}
1728
1729#ifdef CONFIG_STRICT_DEVMEM
1730static int strict_iomem_checks = 1;
1731#else
1732static int strict_iomem_checks;
1733#endif
1734
1735/*
1736 * Check if an address is exclusive to the kernel and must not be mapped to
1737 * user space, for example, via /dev/mem.
1738 *
1739 * Returns true if exclusive to the kernel, otherwise returns false.
1740 */
1741bool resource_is_exclusive(struct resource *root, u64 addr, resource_size_t size)
1742{
1743 const unsigned int exclusive_system_ram = IORESOURCE_SYSTEM_RAM |
1744 IORESOURCE_EXCLUSIVE;
1745 bool skip_children = false, err = false;
1746 struct resource *p;
1747
1748 read_lock(&resource_lock);
1749 for_each_resource(root, p, skip_children) {
1750 if (p->start >= addr + size)
1751 break;
1752 if (p->end < addr) {
1753 skip_children = true;
1754 continue;
1755 }
1756 skip_children = false;
1757
1758 /*
1759 * IORESOURCE_SYSTEM_RAM resources are exclusive if
1760 * IORESOURCE_EXCLUSIVE is set, even if they
1761 * are not busy and even if "iomem=relaxed" is set. The
1762 * responsible driver dynamically adds/removes system RAM within
1763 * such an area and uncontrolled access is dangerous.
1764 */
1765 if ((p->flags & exclusive_system_ram) == exclusive_system_ram) {
1766 err = true;
1767 break;
1768 }
1769
1770 /*
1771 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1772 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1773 * resource is busy.
1774 */
1775 if (!strict_iomem_checks || !(p->flags & IORESOURCE_BUSY))
1776 continue;
1777 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1778 || p->flags & IORESOURCE_EXCLUSIVE) {
1779 err = true;
1780 break;
1781 }
1782 }
1783 read_unlock(&resource_lock);
1784
1785 return err;
1786}
1787
1788bool iomem_is_exclusive(u64 addr)
1789{
1790 return resource_is_exclusive(&iomem_resource, addr & PAGE_MASK,
1791 PAGE_SIZE);
1792}
1793
1794struct resource_entry *resource_list_create_entry(struct resource *res,
1795 size_t extra_size)
1796{
1797 struct resource_entry *entry;
1798
1799 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1800 if (entry) {
1801 INIT_LIST_HEAD(&entry->node);
1802 entry->res = res ? res : &entry->__res;
1803 }
1804
1805 return entry;
1806}
1807EXPORT_SYMBOL(resource_list_create_entry);
1808
1809void resource_list_free(struct list_head *head)
1810{
1811 struct resource_entry *entry, *tmp;
1812
1813 list_for_each_entry_safe(entry, tmp, head, node)
1814 resource_list_destroy_entry(entry);
1815}
1816EXPORT_SYMBOL(resource_list_free);
1817
1818#ifdef CONFIG_GET_FREE_REGION
1819#define GFR_DESCENDING (1UL << 0)
1820#define GFR_REQUEST_REGION (1UL << 1)
1821#define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT)
1822
1823static resource_size_t gfr_start(struct resource *base, resource_size_t size,
1824 resource_size_t align, unsigned long flags)
1825{
1826 if (flags & GFR_DESCENDING) {
1827 resource_size_t end;
1828
1829 end = min_t(resource_size_t, base->end,
1830 (1ULL << MAX_PHYSMEM_BITS) - 1);
1831 return end - size + 1;
1832 }
1833
1834 return ALIGN(base->start, align);
1835}
1836
1837static bool gfr_continue(struct resource *base, resource_size_t addr,
1838 resource_size_t size, unsigned long flags)
1839{
1840 if (flags & GFR_DESCENDING)
1841 return addr > size && addr >= base->start;
1842 /*
1843 * In the ascend case be careful that the last increment by
1844 * @size did not wrap 0.
1845 */
1846 return addr > addr - size &&
1847 addr <= min_t(resource_size_t, base->end,
1848 (1ULL << MAX_PHYSMEM_BITS) - 1);
1849}
1850
1851static resource_size_t gfr_next(resource_size_t addr, resource_size_t size,
1852 unsigned long flags)
1853{
1854 if (flags & GFR_DESCENDING)
1855 return addr - size;
1856 return addr + size;
1857}
1858
1859static void remove_free_mem_region(void *_res)
1860{
1861 struct resource *res = _res;
1862
1863 if (res->parent)
1864 remove_resource(res);
1865 free_resource(res);
1866}
1867
1868static struct resource *
1869get_free_mem_region(struct device *dev, struct resource *base,
1870 resource_size_t size, const unsigned long align,
1871 const char *name, const unsigned long desc,
1872 const unsigned long flags)
1873{
1874 resource_size_t addr;
1875 struct resource *res;
1876 struct region_devres *dr = NULL;
1877
1878 size = ALIGN(size, align);
1879
1880 res = alloc_resource(GFP_KERNEL);
1881 if (!res)
1882 return ERR_PTR(-ENOMEM);
1883
1884 if (dev && (flags & GFR_REQUEST_REGION)) {
1885 dr = devres_alloc(devm_region_release,
1886 sizeof(struct region_devres), GFP_KERNEL);
1887 if (!dr) {
1888 free_resource(res);
1889 return ERR_PTR(-ENOMEM);
1890 }
1891 } else if (dev) {
1892 if (devm_add_action_or_reset(dev, remove_free_mem_region, res))
1893 return ERR_PTR(-ENOMEM);
1894 }
1895
1896 write_lock(&resource_lock);
1897 for (addr = gfr_start(base, size, align, flags);
1898 gfr_continue(base, addr, align, flags);
1899 addr = gfr_next(addr, align, flags)) {
1900 if (__region_intersects(base, addr, size, 0, IORES_DESC_NONE) !=
1901 REGION_DISJOINT)
1902 continue;
1903
1904 if (flags & GFR_REQUEST_REGION) {
1905 if (__request_region_locked(res, &iomem_resource, addr,
1906 size, name, 0))
1907 break;
1908
1909 if (dev) {
1910 dr->parent = &iomem_resource;
1911 dr->start = addr;
1912 dr->n = size;
1913 devres_add(dev, dr);
1914 }
1915
1916 res->desc = desc;
1917 write_unlock(&resource_lock);
1918
1919
1920 /*
1921 * A driver is claiming this region so revoke any
1922 * mappings.
1923 */
1924 revoke_iomem(res);
1925 } else {
1926 res->start = addr;
1927 res->end = addr + size - 1;
1928 res->name = name;
1929 res->desc = desc;
1930 res->flags = IORESOURCE_MEM;
1931
1932 /*
1933 * Only succeed if the resource hosts an exclusive
1934 * range after the insert
1935 */
1936 if (__insert_resource(base, res) || res->child)
1937 break;
1938
1939 write_unlock(&resource_lock);
1940 }
1941
1942 return res;
1943 }
1944 write_unlock(&resource_lock);
1945
1946 if (flags & GFR_REQUEST_REGION) {
1947 free_resource(res);
1948 devres_free(dr);
1949 } else if (dev)
1950 devm_release_action(dev, remove_free_mem_region, res);
1951
1952 return ERR_PTR(-ERANGE);
1953}
1954
1955/**
1956 * devm_request_free_mem_region - find free region for device private memory
1957 *
1958 * @dev: device struct to bind the resource to
1959 * @size: size in bytes of the device memory to add
1960 * @base: resource tree to look in
1961 *
1962 * This function tries to find an empty range of physical address big enough to
1963 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1964 * memory, which in turn allocates struct pages.
1965 */
1966struct resource *devm_request_free_mem_region(struct device *dev,
1967 struct resource *base, unsigned long size)
1968{
1969 unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
1970
1971 return get_free_mem_region(dev, base, size, GFR_DEFAULT_ALIGN,
1972 dev_name(dev),
1973 IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
1974}
1975EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
1976
1977struct resource *request_free_mem_region(struct resource *base,
1978 unsigned long size, const char *name)
1979{
1980 unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
1981
1982 return get_free_mem_region(NULL, base, size, GFR_DEFAULT_ALIGN, name,
1983 IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
1984}
1985EXPORT_SYMBOL_GPL(request_free_mem_region);
1986
1987/**
1988 * alloc_free_mem_region - find a free region relative to @base
1989 * @base: resource that will parent the new resource
1990 * @size: size in bytes of memory to allocate from @base
1991 * @align: alignment requirements for the allocation
1992 * @name: resource name
1993 *
1994 * Buses like CXL, that can dynamically instantiate new memory regions,
1995 * need a method to allocate physical address space for those regions.
1996 * Allocate and insert a new resource to cover a free, unclaimed by a
1997 * descendant of @base, range in the span of @base.
1998 */
1999struct resource *alloc_free_mem_region(struct resource *base,
2000 unsigned long size, unsigned long align,
2001 const char *name)
2002{
2003 /* Default of ascending direction and insert resource */
2004 unsigned long flags = 0;
2005
2006 return get_free_mem_region(NULL, base, size, align, name,
2007 IORES_DESC_NONE, flags);
2008}
2009EXPORT_SYMBOL_NS_GPL(alloc_free_mem_region, CXL);
2010#endif /* CONFIG_GET_FREE_REGION */
2011
2012static int __init strict_iomem(char *str)
2013{
2014 if (strstr(str, "relaxed"))
2015 strict_iomem_checks = 0;
2016 if (strstr(str, "strict"))
2017 strict_iomem_checks = 1;
2018 return 1;
2019}
2020
2021static int iomem_fs_init_fs_context(struct fs_context *fc)
2022{
2023 return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM;
2024}
2025
2026static struct file_system_type iomem_fs_type = {
2027 .name = "iomem",
2028 .owner = THIS_MODULE,
2029 .init_fs_context = iomem_fs_init_fs_context,
2030 .kill_sb = kill_anon_super,
2031};
2032
2033static int __init iomem_init_inode(void)
2034{
2035 static struct vfsmount *iomem_vfs_mount;
2036 static int iomem_fs_cnt;
2037 struct inode *inode;
2038 int rc;
2039
2040 rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt);
2041 if (rc < 0) {
2042 pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc);
2043 return rc;
2044 }
2045
2046 inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb);
2047 if (IS_ERR(inode)) {
2048 rc = PTR_ERR(inode);
2049 pr_err("Cannot allocate inode for iomem: %d\n", rc);
2050 simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt);
2051 return rc;
2052 }
2053
2054 /*
2055 * Publish iomem revocation inode initialized.
2056 * Pairs with smp_load_acquire() in revoke_iomem().
2057 */
2058 smp_store_release(&iomem_inode, inode);
2059
2060 return 0;
2061}
2062
2063fs_initcall(iomem_init_inode);
2064
2065__setup("iomem=", strict_iomem);