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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 <mj@ucw.cz>
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/sched.h>
22#include <linux/seq_file.h>
23#include <linux/device.h>
24#include <linux/pfn.h>
25#include <linux/mm.h>
26#include <linux/resource_ext.h>
27#include <asm/io.h>
28
29
30struct resource ioport_resource = {
31 .name = "PCI IO",
32 .start = 0,
33 .end = IO_SPACE_LIMIT,
34 .flags = IORESOURCE_IO,
35};
36EXPORT_SYMBOL(ioport_resource);
37
38struct resource iomem_resource = {
39 .name = "PCI mem",
40 .start = 0,
41 .end = -1,
42 .flags = IORESOURCE_MEM,
43};
44EXPORT_SYMBOL(iomem_resource);
45
46/* constraints to be met while allocating resources */
47struct resource_constraint {
48 resource_size_t min, max, align;
49 resource_size_t (*alignf)(void *, const struct resource *,
50 resource_size_t, resource_size_t);
51 void *alignf_data;
52};
53
54static DEFINE_RWLOCK(resource_lock);
55
56/*
57 * For memory hotplug, there is no way to free resource entries allocated
58 * by boot mem after the system is up. So for reusing the resource entry
59 * we need to remember the resource.
60 */
61static struct resource *bootmem_resource_free;
62static DEFINE_SPINLOCK(bootmem_resource_lock);
63
64static struct resource *next_resource(struct resource *p, bool sibling_only)
65{
66 /* Caller wants to traverse through siblings only */
67 if (sibling_only)
68 return p->sibling;
69
70 if (p->child)
71 return p->child;
72 while (!p->sibling && p->parent)
73 p = p->parent;
74 return p->sibling;
75}
76
77static void *r_next(struct seq_file *m, void *v, loff_t *pos)
78{
79 struct resource *p = v;
80 (*pos)++;
81 return (void *)next_resource(p, false);
82}
83
84#ifdef CONFIG_PROC_FS
85
86enum { MAX_IORES_LEVEL = 5 };
87
88static void *r_start(struct seq_file *m, loff_t *pos)
89 __acquires(resource_lock)
90{
91 struct resource *p = PDE_DATA(file_inode(m->file));
92 loff_t l = 0;
93 read_lock(&resource_lock);
94 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
95 ;
96 return p;
97}
98
99static void r_stop(struct seq_file *m, void *v)
100 __releases(resource_lock)
101{
102 read_unlock(&resource_lock);
103}
104
105static int r_show(struct seq_file *m, void *v)
106{
107 struct resource *root = PDE_DATA(file_inode(m->file));
108 struct resource *r = v, *p;
109 unsigned long long start, end;
110 int width = root->end < 0x10000 ? 4 : 8;
111 int depth;
112
113 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
114 if (p->parent == root)
115 break;
116
117 if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
118 start = r->start;
119 end = r->end;
120 } else {
121 start = end = 0;
122 }
123
124 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
125 depth * 2, "",
126 width, start,
127 width, end,
128 r->name ? r->name : "<BAD>");
129 return 0;
130}
131
132static const struct seq_operations resource_op = {
133 .start = r_start,
134 .next = r_next,
135 .stop = r_stop,
136 .show = r_show,
137};
138
139static int __init ioresources_init(void)
140{
141 proc_create_seq_data("ioports", 0, NULL, &resource_op,
142 &ioport_resource);
143 proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource);
144 return 0;
145}
146__initcall(ioresources_init);
147
148#endif /* CONFIG_PROC_FS */
149
150static void free_resource(struct resource *res)
151{
152 if (!res)
153 return;
154
155 if (!PageSlab(virt_to_head_page(res))) {
156 spin_lock(&bootmem_resource_lock);
157 res->sibling = bootmem_resource_free;
158 bootmem_resource_free = res;
159 spin_unlock(&bootmem_resource_lock);
160 } else {
161 kfree(res);
162 }
163}
164
165static struct resource *alloc_resource(gfp_t flags)
166{
167 struct resource *res = NULL;
168
169 spin_lock(&bootmem_resource_lock);
170 if (bootmem_resource_free) {
171 res = bootmem_resource_free;
172 bootmem_resource_free = res->sibling;
173 }
174 spin_unlock(&bootmem_resource_lock);
175
176 if (res)
177 memset(res, 0, sizeof(struct resource));
178 else
179 res = kzalloc(sizeof(struct resource), flags);
180
181 return res;
182}
183
184/* Return the conflict entry if you can't request it */
185static struct resource * __request_resource(struct resource *root, struct resource *new)
186{
187 resource_size_t start = new->start;
188 resource_size_t end = new->end;
189 struct resource *tmp, **p;
190
191 if (end < start)
192 return root;
193 if (start < root->start)
194 return root;
195 if (end > root->end)
196 return root;
197 p = &root->child;
198 for (;;) {
199 tmp = *p;
200 if (!tmp || tmp->start > end) {
201 new->sibling = tmp;
202 *p = new;
203 new->parent = root;
204 return NULL;
205 }
206 p = &tmp->sibling;
207 if (tmp->end < start)
208 continue;
209 return tmp;
210 }
211}
212
213static int __release_resource(struct resource *old, bool release_child)
214{
215 struct resource *tmp, **p, *chd;
216
217 p = &old->parent->child;
218 for (;;) {
219 tmp = *p;
220 if (!tmp)
221 break;
222 if (tmp == old) {
223 if (release_child || !(tmp->child)) {
224 *p = tmp->sibling;
225 } else {
226 for (chd = tmp->child;; chd = chd->sibling) {
227 chd->parent = tmp->parent;
228 if (!(chd->sibling))
229 break;
230 }
231 *p = tmp->child;
232 chd->sibling = tmp->sibling;
233 }
234 old->parent = NULL;
235 return 0;
236 }
237 p = &tmp->sibling;
238 }
239 return -EINVAL;
240}
241
242static void __release_child_resources(struct resource *r)
243{
244 struct resource *tmp, *p;
245 resource_size_t size;
246
247 p = r->child;
248 r->child = NULL;
249 while (p) {
250 tmp = p;
251 p = p->sibling;
252
253 tmp->parent = NULL;
254 tmp->sibling = NULL;
255 __release_child_resources(tmp);
256
257 printk(KERN_DEBUG "release child resource %pR\n", tmp);
258 /* need to restore size, and keep flags */
259 size = resource_size(tmp);
260 tmp->start = 0;
261 tmp->end = size - 1;
262 }
263}
264
265void release_child_resources(struct resource *r)
266{
267 write_lock(&resource_lock);
268 __release_child_resources(r);
269 write_unlock(&resource_lock);
270}
271
272/**
273 * request_resource_conflict - request and reserve an I/O or memory resource
274 * @root: root resource descriptor
275 * @new: resource descriptor desired by caller
276 *
277 * Returns 0 for success, conflict resource on error.
278 */
279struct resource *request_resource_conflict(struct resource *root, struct resource *new)
280{
281 struct resource *conflict;
282
283 write_lock(&resource_lock);
284 conflict = __request_resource(root, new);
285 write_unlock(&resource_lock);
286 return conflict;
287}
288
289/**
290 * request_resource - request and reserve an I/O or memory resource
291 * @root: root resource descriptor
292 * @new: resource descriptor desired by caller
293 *
294 * Returns 0 for success, negative error code on error.
295 */
296int request_resource(struct resource *root, struct resource *new)
297{
298 struct resource *conflict;
299
300 conflict = request_resource_conflict(root, new);
301 return conflict ? -EBUSY : 0;
302}
303
304EXPORT_SYMBOL(request_resource);
305
306/**
307 * release_resource - release a previously reserved resource
308 * @old: resource pointer
309 */
310int release_resource(struct resource *old)
311{
312 int retval;
313
314 write_lock(&resource_lock);
315 retval = __release_resource(old, true);
316 write_unlock(&resource_lock);
317 return retval;
318}
319
320EXPORT_SYMBOL(release_resource);
321
322/**
323 * Finds the lowest iomem resource that covers part of [@start..@end]. The
324 * caller must specify @start, @end, @flags, and @desc (which may be
325 * IORES_DESC_NONE).
326 *
327 * If a resource is found, returns 0 and @*res is overwritten with the part
328 * of the resource that's within [@start..@end]; if none is found, returns
329 * -ENODEV. Returns -EINVAL for invalid parameters.
330 *
331 * This function walks the whole tree and not just first level children
332 * unless @first_lvl is true.
333 *
334 * @start: start address of the resource searched for
335 * @end: end address of same resource
336 * @flags: flags which the resource must have
337 * @desc: descriptor the resource must have
338 * @first_lvl: walk only the first level children, if set
339 * @res: return ptr, if resource found
340 */
341static int find_next_iomem_res(resource_size_t start, resource_size_t end,
342 unsigned long flags, unsigned long desc,
343 bool first_lvl, struct resource *res)
344{
345 bool siblings_only = true;
346 struct resource *p;
347
348 if (!res)
349 return -EINVAL;
350
351 if (start >= end)
352 return -EINVAL;
353
354 read_lock(&resource_lock);
355
356 for (p = iomem_resource.child; p; p = next_resource(p, siblings_only)) {
357 /* If we passed the resource we are looking for, stop */
358 if (p->start > end) {
359 p = NULL;
360 break;
361 }
362
363 /* Skip until we find a range that matches what we look for */
364 if (p->end < start)
365 continue;
366
367 /*
368 * Now that we found a range that matches what we look for,
369 * check the flags and the descriptor. If we were not asked to
370 * use only the first level, start looking at children as well.
371 */
372 siblings_only = first_lvl;
373
374 if ((p->flags & flags) != flags)
375 continue;
376 if ((desc != IORES_DESC_NONE) && (desc != p->desc))
377 continue;
378
379 /* Found a match, break */
380 break;
381 }
382
383 if (p) {
384 /* copy data */
385 res->start = max(start, p->start);
386 res->end = min(end, p->end);
387 res->flags = p->flags;
388 res->desc = p->desc;
389 }
390
391 read_unlock(&resource_lock);
392 return p ? 0 : -ENODEV;
393}
394
395static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
396 unsigned long flags, unsigned long desc,
397 bool first_lvl, void *arg,
398 int (*func)(struct resource *, void *))
399{
400 struct resource res;
401 int ret = -EINVAL;
402
403 while (start < end &&
404 !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) {
405 ret = (*func)(&res, arg);
406 if (ret)
407 break;
408
409 start = res.end + 1;
410 }
411
412 return ret;
413}
414
415/**
416 * Walks through iomem resources and calls func() with matching resource
417 * ranges. This walks through whole tree and not just first level children.
418 * All the memory ranges which overlap start,end and also match flags and
419 * desc are valid candidates.
420 *
421 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
422 * @flags: I/O resource flags
423 * @start: start addr
424 * @end: end addr
425 * @arg: function argument for the callback @func
426 * @func: callback function that is called for each qualifying resource area
427 *
428 * NOTE: For a new descriptor search, define a new IORES_DESC in
429 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
430 */
431int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
432 u64 end, void *arg, int (*func)(struct resource *, void *))
433{
434 return __walk_iomem_res_desc(start, end, flags, desc, false, arg, func);
435}
436EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
437
438/*
439 * This function calls the @func callback against all memory ranges of type
440 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
441 * Now, this function is only for System RAM, it deals with full ranges and
442 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
443 * ranges.
444 */
445int walk_system_ram_res(u64 start, u64 end, void *arg,
446 int (*func)(struct resource *, void *))
447{
448 unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
449
450 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
451 arg, func);
452}
453
454/*
455 * This function calls the @func callback against all memory ranges, which
456 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
457 */
458int walk_mem_res(u64 start, u64 end, void *arg,
459 int (*func)(struct resource *, void *))
460{
461 unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
462
463 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
464 arg, func);
465}
466
467/*
468 * This function calls the @func callback against all memory ranges of type
469 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
470 * It is to be used only for System RAM.
471 *
472 * This will find System RAM ranges that are children of top-level resources
473 * in addition to top-level System RAM resources.
474 */
475int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
476 void *arg, int (*func)(unsigned long, unsigned long, void *))
477{
478 resource_size_t start, end;
479 unsigned long flags;
480 struct resource res;
481 unsigned long pfn, end_pfn;
482 int ret = -EINVAL;
483
484 start = (u64) start_pfn << PAGE_SHIFT;
485 end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
486 flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
487 while (start < end &&
488 !find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
489 false, &res)) {
490 pfn = PFN_UP(res.start);
491 end_pfn = PFN_DOWN(res.end + 1);
492 if (end_pfn > pfn)
493 ret = (*func)(pfn, end_pfn - pfn, arg);
494 if (ret)
495 break;
496 start = res.end + 1;
497 }
498 return ret;
499}
500
501static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
502{
503 return 1;
504}
505
506/*
507 * This generic page_is_ram() returns true if specified address is
508 * registered as System RAM in iomem_resource list.
509 */
510int __weak page_is_ram(unsigned long pfn)
511{
512 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
513}
514EXPORT_SYMBOL_GPL(page_is_ram);
515
516/**
517 * region_intersects() - determine intersection of region with known resources
518 * @start: region start address
519 * @size: size of region
520 * @flags: flags of resource (in iomem_resource)
521 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
522 *
523 * Check if the specified region partially overlaps or fully eclipses a
524 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
525 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
526 * return REGION_MIXED if the region overlaps @flags/@desc and another
527 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
528 * and no other defined resource. Note that REGION_INTERSECTS is also
529 * returned in the case when the specified region overlaps RAM and undefined
530 * memory holes.
531 *
532 * region_intersect() is used by memory remapping functions to ensure
533 * the user is not remapping RAM and is a vast speed up over walking
534 * through the resource table page by page.
535 */
536int region_intersects(resource_size_t start, size_t size, unsigned long flags,
537 unsigned long desc)
538{
539 struct resource res;
540 int type = 0; int other = 0;
541 struct resource *p;
542
543 res.start = start;
544 res.end = start + size - 1;
545
546 read_lock(&resource_lock);
547 for (p = iomem_resource.child; p ; p = p->sibling) {
548 bool is_type = (((p->flags & flags) == flags) &&
549 ((desc == IORES_DESC_NONE) ||
550 (desc == p->desc)));
551
552 if (resource_overlaps(p, &res))
553 is_type ? type++ : other++;
554 }
555 read_unlock(&resource_lock);
556
557 if (other == 0)
558 return type ? REGION_INTERSECTS : REGION_DISJOINT;
559
560 if (type)
561 return REGION_MIXED;
562
563 return REGION_DISJOINT;
564}
565EXPORT_SYMBOL_GPL(region_intersects);
566
567void __weak arch_remove_reservations(struct resource *avail)
568{
569}
570
571static resource_size_t simple_align_resource(void *data,
572 const struct resource *avail,
573 resource_size_t size,
574 resource_size_t align)
575{
576 return avail->start;
577}
578
579static void resource_clip(struct resource *res, resource_size_t min,
580 resource_size_t max)
581{
582 if (res->start < min)
583 res->start = min;
584 if (res->end > max)
585 res->end = max;
586}
587
588/*
589 * Find empty slot in the resource tree with the given range and
590 * alignment constraints
591 */
592static int __find_resource(struct resource *root, struct resource *old,
593 struct resource *new,
594 resource_size_t size,
595 struct resource_constraint *constraint)
596{
597 struct resource *this = root->child;
598 struct resource tmp = *new, avail, alloc;
599
600 tmp.start = root->start;
601 /*
602 * Skip past an allocated resource that starts at 0, since the assignment
603 * of this->start - 1 to tmp->end below would cause an underflow.
604 */
605 if (this && this->start == root->start) {
606 tmp.start = (this == old) ? old->start : this->end + 1;
607 this = this->sibling;
608 }
609 for(;;) {
610 if (this)
611 tmp.end = (this == old) ? this->end : this->start - 1;
612 else
613 tmp.end = root->end;
614
615 if (tmp.end < tmp.start)
616 goto next;
617
618 resource_clip(&tmp, constraint->min, constraint->max);
619 arch_remove_reservations(&tmp);
620
621 /* Check for overflow after ALIGN() */
622 avail.start = ALIGN(tmp.start, constraint->align);
623 avail.end = tmp.end;
624 avail.flags = new->flags & ~IORESOURCE_UNSET;
625 if (avail.start >= tmp.start) {
626 alloc.flags = avail.flags;
627 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
628 size, constraint->align);
629 alloc.end = alloc.start + size - 1;
630 if (alloc.start <= alloc.end &&
631 resource_contains(&avail, &alloc)) {
632 new->start = alloc.start;
633 new->end = alloc.end;
634 return 0;
635 }
636 }
637
638next: if (!this || this->end == root->end)
639 break;
640
641 if (this != old)
642 tmp.start = this->end + 1;
643 this = this->sibling;
644 }
645 return -EBUSY;
646}
647
648/*
649 * Find empty slot in the resource tree given range and alignment.
650 */
651static int find_resource(struct resource *root, struct resource *new,
652 resource_size_t size,
653 struct resource_constraint *constraint)
654{
655 return __find_resource(root, NULL, new, size, constraint);
656}
657
658/**
659 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
660 * The resource will be relocated if the new size cannot be reallocated in the
661 * current location.
662 *
663 * @root: root resource descriptor
664 * @old: resource descriptor desired by caller
665 * @newsize: new size of the resource descriptor
666 * @constraint: the size and alignment constraints to be met.
667 */
668static int reallocate_resource(struct resource *root, struct resource *old,
669 resource_size_t newsize,
670 struct resource_constraint *constraint)
671{
672 int err=0;
673 struct resource new = *old;
674 struct resource *conflict;
675
676 write_lock(&resource_lock);
677
678 if ((err = __find_resource(root, old, &new, newsize, constraint)))
679 goto out;
680
681 if (resource_contains(&new, old)) {
682 old->start = new.start;
683 old->end = new.end;
684 goto out;
685 }
686
687 if (old->child) {
688 err = -EBUSY;
689 goto out;
690 }
691
692 if (resource_contains(old, &new)) {
693 old->start = new.start;
694 old->end = new.end;
695 } else {
696 __release_resource(old, true);
697 *old = new;
698 conflict = __request_resource(root, old);
699 BUG_ON(conflict);
700 }
701out:
702 write_unlock(&resource_lock);
703 return err;
704}
705
706
707/**
708 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
709 * The resource will be reallocated with a new size if it was already allocated
710 * @root: root resource descriptor
711 * @new: resource descriptor desired by caller
712 * @size: requested resource region size
713 * @min: minimum boundary to allocate
714 * @max: maximum boundary to allocate
715 * @align: alignment requested, in bytes
716 * @alignf: alignment function, optional, called if not NULL
717 * @alignf_data: arbitrary data to pass to the @alignf function
718 */
719int allocate_resource(struct resource *root, struct resource *new,
720 resource_size_t size, resource_size_t min,
721 resource_size_t max, resource_size_t align,
722 resource_size_t (*alignf)(void *,
723 const struct resource *,
724 resource_size_t,
725 resource_size_t),
726 void *alignf_data)
727{
728 int err;
729 struct resource_constraint constraint;
730
731 if (!alignf)
732 alignf = simple_align_resource;
733
734 constraint.min = min;
735 constraint.max = max;
736 constraint.align = align;
737 constraint.alignf = alignf;
738 constraint.alignf_data = alignf_data;
739
740 if ( new->parent ) {
741 /* resource is already allocated, try reallocating with
742 the new constraints */
743 return reallocate_resource(root, new, size, &constraint);
744 }
745
746 write_lock(&resource_lock);
747 err = find_resource(root, new, size, &constraint);
748 if (err >= 0 && __request_resource(root, new))
749 err = -EBUSY;
750 write_unlock(&resource_lock);
751 return err;
752}
753
754EXPORT_SYMBOL(allocate_resource);
755
756/**
757 * lookup_resource - find an existing resource by a resource start address
758 * @root: root resource descriptor
759 * @start: resource start address
760 *
761 * Returns a pointer to the resource if found, NULL otherwise
762 */
763struct resource *lookup_resource(struct resource *root, resource_size_t start)
764{
765 struct resource *res;
766
767 read_lock(&resource_lock);
768 for (res = root->child; res; res = res->sibling) {
769 if (res->start == start)
770 break;
771 }
772 read_unlock(&resource_lock);
773
774 return res;
775}
776
777/*
778 * Insert a resource into the resource tree. If successful, return NULL,
779 * otherwise return the conflicting resource (compare to __request_resource())
780 */
781static struct resource * __insert_resource(struct resource *parent, struct resource *new)
782{
783 struct resource *first, *next;
784
785 for (;; parent = first) {
786 first = __request_resource(parent, new);
787 if (!first)
788 return first;
789
790 if (first == parent)
791 return first;
792 if (WARN_ON(first == new)) /* duplicated insertion */
793 return first;
794
795 if ((first->start > new->start) || (first->end < new->end))
796 break;
797 if ((first->start == new->start) && (first->end == new->end))
798 break;
799 }
800
801 for (next = first; ; next = next->sibling) {
802 /* Partial overlap? Bad, and unfixable */
803 if (next->start < new->start || next->end > new->end)
804 return next;
805 if (!next->sibling)
806 break;
807 if (next->sibling->start > new->end)
808 break;
809 }
810
811 new->parent = parent;
812 new->sibling = next->sibling;
813 new->child = first;
814
815 next->sibling = NULL;
816 for (next = first; next; next = next->sibling)
817 next->parent = new;
818
819 if (parent->child == first) {
820 parent->child = new;
821 } else {
822 next = parent->child;
823 while (next->sibling != first)
824 next = next->sibling;
825 next->sibling = new;
826 }
827 return NULL;
828}
829
830/**
831 * insert_resource_conflict - Inserts resource in the resource tree
832 * @parent: parent of the new resource
833 * @new: new resource to insert
834 *
835 * Returns 0 on success, conflict resource if the resource can't be inserted.
836 *
837 * This function is equivalent to request_resource_conflict when no conflict
838 * happens. If a conflict happens, and the conflicting resources
839 * entirely fit within the range of the new resource, then the new
840 * resource is inserted and the conflicting resources become children of
841 * the new resource.
842 *
843 * This function is intended for producers of resources, such as FW modules
844 * and bus drivers.
845 */
846struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
847{
848 struct resource *conflict;
849
850 write_lock(&resource_lock);
851 conflict = __insert_resource(parent, new);
852 write_unlock(&resource_lock);
853 return conflict;
854}
855
856/**
857 * insert_resource - Inserts a resource in the resource tree
858 * @parent: parent of the new resource
859 * @new: new resource to insert
860 *
861 * Returns 0 on success, -EBUSY if the resource can't be inserted.
862 *
863 * This function is intended for producers of resources, such as FW modules
864 * and bus drivers.
865 */
866int insert_resource(struct resource *parent, struct resource *new)
867{
868 struct resource *conflict;
869
870 conflict = insert_resource_conflict(parent, new);
871 return conflict ? -EBUSY : 0;
872}
873EXPORT_SYMBOL_GPL(insert_resource);
874
875/**
876 * insert_resource_expand_to_fit - Insert a resource into the resource tree
877 * @root: root resource descriptor
878 * @new: new resource to insert
879 *
880 * Insert a resource into the resource tree, possibly expanding it in order
881 * to make it encompass any conflicting resources.
882 */
883void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
884{
885 if (new->parent)
886 return;
887
888 write_lock(&resource_lock);
889 for (;;) {
890 struct resource *conflict;
891
892 conflict = __insert_resource(root, new);
893 if (!conflict)
894 break;
895 if (conflict == root)
896 break;
897
898 /* Ok, expand resource to cover the conflict, then try again .. */
899 if (conflict->start < new->start)
900 new->start = conflict->start;
901 if (conflict->end > new->end)
902 new->end = conflict->end;
903
904 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
905 }
906 write_unlock(&resource_lock);
907}
908
909/**
910 * remove_resource - Remove a resource in the resource tree
911 * @old: resource to remove
912 *
913 * Returns 0 on success, -EINVAL if the resource is not valid.
914 *
915 * This function removes a resource previously inserted by insert_resource()
916 * or insert_resource_conflict(), and moves the children (if any) up to
917 * where they were before. insert_resource() and insert_resource_conflict()
918 * insert a new resource, and move any conflicting resources down to the
919 * children of the new resource.
920 *
921 * insert_resource(), insert_resource_conflict() and remove_resource() are
922 * intended for producers of resources, such as FW modules and bus drivers.
923 */
924int remove_resource(struct resource *old)
925{
926 int retval;
927
928 write_lock(&resource_lock);
929 retval = __release_resource(old, false);
930 write_unlock(&resource_lock);
931 return retval;
932}
933EXPORT_SYMBOL_GPL(remove_resource);
934
935static int __adjust_resource(struct resource *res, resource_size_t start,
936 resource_size_t size)
937{
938 struct resource *tmp, *parent = res->parent;
939 resource_size_t end = start + size - 1;
940 int result = -EBUSY;
941
942 if (!parent)
943 goto skip;
944
945 if ((start < parent->start) || (end > parent->end))
946 goto out;
947
948 if (res->sibling && (res->sibling->start <= end))
949 goto out;
950
951 tmp = parent->child;
952 if (tmp != res) {
953 while (tmp->sibling != res)
954 tmp = tmp->sibling;
955 if (start <= tmp->end)
956 goto out;
957 }
958
959skip:
960 for (tmp = res->child; tmp; tmp = tmp->sibling)
961 if ((tmp->start < start) || (tmp->end > end))
962 goto out;
963
964 res->start = start;
965 res->end = end;
966 result = 0;
967
968 out:
969 return result;
970}
971
972/**
973 * adjust_resource - modify a resource's start and size
974 * @res: resource to modify
975 * @start: new start value
976 * @size: new size
977 *
978 * Given an existing resource, change its start and size to match the
979 * arguments. Returns 0 on success, -EBUSY if it can't fit.
980 * Existing children of the resource are assumed to be immutable.
981 */
982int adjust_resource(struct resource *res, resource_size_t start,
983 resource_size_t size)
984{
985 int result;
986
987 write_lock(&resource_lock);
988 result = __adjust_resource(res, start, size);
989 write_unlock(&resource_lock);
990 return result;
991}
992EXPORT_SYMBOL(adjust_resource);
993
994static void __init
995__reserve_region_with_split(struct resource *root, resource_size_t start,
996 resource_size_t end, const char *name)
997{
998 struct resource *parent = root;
999 struct resource *conflict;
1000 struct resource *res = alloc_resource(GFP_ATOMIC);
1001 struct resource *next_res = NULL;
1002 int type = resource_type(root);
1003
1004 if (!res)
1005 return;
1006
1007 res->name = name;
1008 res->start = start;
1009 res->end = end;
1010 res->flags = type | IORESOURCE_BUSY;
1011 res->desc = IORES_DESC_NONE;
1012
1013 while (1) {
1014
1015 conflict = __request_resource(parent, res);
1016 if (!conflict) {
1017 if (!next_res)
1018 break;
1019 res = next_res;
1020 next_res = NULL;
1021 continue;
1022 }
1023
1024 /* conflict covered whole area */
1025 if (conflict->start <= res->start &&
1026 conflict->end >= res->end) {
1027 free_resource(res);
1028 WARN_ON(next_res);
1029 break;
1030 }
1031
1032 /* failed, split and try again */
1033 if (conflict->start > res->start) {
1034 end = res->end;
1035 res->end = conflict->start - 1;
1036 if (conflict->end < end) {
1037 next_res = alloc_resource(GFP_ATOMIC);
1038 if (!next_res) {
1039 free_resource(res);
1040 break;
1041 }
1042 next_res->name = name;
1043 next_res->start = conflict->end + 1;
1044 next_res->end = end;
1045 next_res->flags = type | IORESOURCE_BUSY;
1046 next_res->desc = IORES_DESC_NONE;
1047 }
1048 } else {
1049 res->start = conflict->end + 1;
1050 }
1051 }
1052
1053}
1054
1055void __init
1056reserve_region_with_split(struct resource *root, resource_size_t start,
1057 resource_size_t end, const char *name)
1058{
1059 int abort = 0;
1060
1061 write_lock(&resource_lock);
1062 if (root->start > start || root->end < end) {
1063 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1064 (unsigned long long)start, (unsigned long long)end,
1065 root);
1066 if (start > root->end || end < root->start)
1067 abort = 1;
1068 else {
1069 if (end > root->end)
1070 end = root->end;
1071 if (start < root->start)
1072 start = root->start;
1073 pr_err("fixing request to [0x%llx-0x%llx]\n",
1074 (unsigned long long)start,
1075 (unsigned long long)end);
1076 }
1077 dump_stack();
1078 }
1079 if (!abort)
1080 __reserve_region_with_split(root, start, end, name);
1081 write_unlock(&resource_lock);
1082}
1083
1084/**
1085 * resource_alignment - calculate resource's alignment
1086 * @res: resource pointer
1087 *
1088 * Returns alignment on success, 0 (invalid alignment) on failure.
1089 */
1090resource_size_t resource_alignment(struct resource *res)
1091{
1092 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1093 case IORESOURCE_SIZEALIGN:
1094 return resource_size(res);
1095 case IORESOURCE_STARTALIGN:
1096 return res->start;
1097 default:
1098 return 0;
1099 }
1100}
1101
1102/*
1103 * This is compatibility stuff for IO resources.
1104 *
1105 * Note how this, unlike the above, knows about
1106 * the IO flag meanings (busy etc).
1107 *
1108 * request_region creates a new busy region.
1109 *
1110 * release_region releases a matching busy region.
1111 */
1112
1113static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1114
1115/**
1116 * __request_region - create a new busy resource region
1117 * @parent: parent resource descriptor
1118 * @start: resource start address
1119 * @n: resource region size
1120 * @name: reserving caller's ID string
1121 * @flags: IO resource flags
1122 */
1123struct resource * __request_region(struct resource *parent,
1124 resource_size_t start, resource_size_t n,
1125 const char *name, int flags)
1126{
1127 DECLARE_WAITQUEUE(wait, current);
1128 struct resource *res = alloc_resource(GFP_KERNEL);
1129
1130 if (!res)
1131 return NULL;
1132
1133 res->name = name;
1134 res->start = start;
1135 res->end = start + n - 1;
1136
1137 write_lock(&resource_lock);
1138
1139 for (;;) {
1140 struct resource *conflict;
1141
1142 res->flags = resource_type(parent) | resource_ext_type(parent);
1143 res->flags |= IORESOURCE_BUSY | flags;
1144 res->desc = parent->desc;
1145
1146 conflict = __request_resource(parent, res);
1147 if (!conflict)
1148 break;
1149 /*
1150 * mm/hmm.c reserves physical addresses which then
1151 * become unavailable to other users. Conflicts are
1152 * not expected. Warn to aid debugging if encountered.
1153 */
1154 if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1155 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1156 conflict->name, conflict, res);
1157 }
1158 if (conflict != parent) {
1159 if (!(conflict->flags & IORESOURCE_BUSY)) {
1160 parent = conflict;
1161 continue;
1162 }
1163 }
1164 if (conflict->flags & flags & IORESOURCE_MUXED) {
1165 add_wait_queue(&muxed_resource_wait, &wait);
1166 write_unlock(&resource_lock);
1167 set_current_state(TASK_UNINTERRUPTIBLE);
1168 schedule();
1169 remove_wait_queue(&muxed_resource_wait, &wait);
1170 write_lock(&resource_lock);
1171 continue;
1172 }
1173 /* Uhhuh, that didn't work out.. */
1174 free_resource(res);
1175 res = NULL;
1176 break;
1177 }
1178 write_unlock(&resource_lock);
1179 return res;
1180}
1181EXPORT_SYMBOL(__request_region);
1182
1183/**
1184 * __release_region - release a previously reserved resource region
1185 * @parent: parent resource descriptor
1186 * @start: resource start address
1187 * @n: resource region size
1188 *
1189 * The described resource region must match a currently busy region.
1190 */
1191void __release_region(struct resource *parent, resource_size_t start,
1192 resource_size_t n)
1193{
1194 struct resource **p;
1195 resource_size_t end;
1196
1197 p = &parent->child;
1198 end = start + n - 1;
1199
1200 write_lock(&resource_lock);
1201
1202 for (;;) {
1203 struct resource *res = *p;
1204
1205 if (!res)
1206 break;
1207 if (res->start <= start && res->end >= end) {
1208 if (!(res->flags & IORESOURCE_BUSY)) {
1209 p = &res->child;
1210 continue;
1211 }
1212 if (res->start != start || res->end != end)
1213 break;
1214 *p = res->sibling;
1215 write_unlock(&resource_lock);
1216 if (res->flags & IORESOURCE_MUXED)
1217 wake_up(&muxed_resource_wait);
1218 free_resource(res);
1219 return;
1220 }
1221 p = &res->sibling;
1222 }
1223
1224 write_unlock(&resource_lock);
1225
1226 printk(KERN_WARNING "Trying to free nonexistent resource "
1227 "<%016llx-%016llx>\n", (unsigned long long)start,
1228 (unsigned long long)end);
1229}
1230EXPORT_SYMBOL(__release_region);
1231
1232#ifdef CONFIG_MEMORY_HOTREMOVE
1233/**
1234 * release_mem_region_adjustable - release a previously reserved memory region
1235 * @parent: parent resource descriptor
1236 * @start: resource start address
1237 * @size: resource region size
1238 *
1239 * This interface is intended for memory hot-delete. The requested region
1240 * is released from a currently busy memory resource. The requested region
1241 * must either match exactly or fit into a single busy resource entry. In
1242 * the latter case, the remaining resource is adjusted accordingly.
1243 * Existing children of the busy memory resource must be immutable in the
1244 * request.
1245 *
1246 * Note:
1247 * - Additional release conditions, such as overlapping region, can be
1248 * supported after they are confirmed as valid cases.
1249 * - When a busy memory resource gets split into two entries, the code
1250 * assumes that all children remain in the lower address entry for
1251 * simplicity. Enhance this logic when necessary.
1252 */
1253int release_mem_region_adjustable(struct resource *parent,
1254 resource_size_t start, resource_size_t size)
1255{
1256 struct resource **p;
1257 struct resource *res;
1258 struct resource *new_res;
1259 resource_size_t end;
1260 int ret = -EINVAL;
1261
1262 end = start + size - 1;
1263 if ((start < parent->start) || (end > parent->end))
1264 return ret;
1265
1266 /* The alloc_resource() result gets checked later */
1267 new_res = alloc_resource(GFP_KERNEL);
1268
1269 p = &parent->child;
1270 write_lock(&resource_lock);
1271
1272 while ((res = *p)) {
1273 if (res->start >= end)
1274 break;
1275
1276 /* look for the next resource if it does not fit into */
1277 if (res->start > start || res->end < end) {
1278 p = &res->sibling;
1279 continue;
1280 }
1281
1282 /*
1283 * All memory regions added from memory-hotplug path have the
1284 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1285 * this flag, we know that we are dealing with a resource coming
1286 * from HMM/devm. HMM/devm use another mechanism to add/release
1287 * a resource. This goes via devm_request_mem_region and
1288 * devm_release_mem_region.
1289 * HMM/devm take care to release their resources when they want,
1290 * so if we are dealing with them, let us just back off here.
1291 */
1292 if (!(res->flags & IORESOURCE_SYSRAM)) {
1293 ret = 0;
1294 break;
1295 }
1296
1297 if (!(res->flags & IORESOURCE_MEM))
1298 break;
1299
1300 if (!(res->flags & IORESOURCE_BUSY)) {
1301 p = &res->child;
1302 continue;
1303 }
1304
1305 /* found the target resource; let's adjust accordingly */
1306 if (res->start == start && res->end == end) {
1307 /* free the whole entry */
1308 *p = res->sibling;
1309 free_resource(res);
1310 ret = 0;
1311 } else if (res->start == start && res->end != end) {
1312 /* adjust the start */
1313 ret = __adjust_resource(res, end + 1,
1314 res->end - end);
1315 } else if (res->start != start && res->end == end) {
1316 /* adjust the end */
1317 ret = __adjust_resource(res, res->start,
1318 start - res->start);
1319 } else {
1320 /* split into two entries */
1321 if (!new_res) {
1322 ret = -ENOMEM;
1323 break;
1324 }
1325 new_res->name = res->name;
1326 new_res->start = end + 1;
1327 new_res->end = res->end;
1328 new_res->flags = res->flags;
1329 new_res->desc = res->desc;
1330 new_res->parent = res->parent;
1331 new_res->sibling = res->sibling;
1332 new_res->child = NULL;
1333
1334 ret = __adjust_resource(res, res->start,
1335 start - res->start);
1336 if (ret)
1337 break;
1338 res->sibling = new_res;
1339 new_res = NULL;
1340 }
1341
1342 break;
1343 }
1344
1345 write_unlock(&resource_lock);
1346 free_resource(new_res);
1347 return ret;
1348}
1349#endif /* CONFIG_MEMORY_HOTREMOVE */
1350
1351/*
1352 * Managed region resource
1353 */
1354static void devm_resource_release(struct device *dev, void *ptr)
1355{
1356 struct resource **r = ptr;
1357
1358 release_resource(*r);
1359}
1360
1361/**
1362 * devm_request_resource() - request and reserve an I/O or memory resource
1363 * @dev: device for which to request the resource
1364 * @root: root of the resource tree from which to request the resource
1365 * @new: descriptor of the resource to request
1366 *
1367 * This is a device-managed version of request_resource(). There is usually
1368 * no need to release resources requested by this function explicitly since
1369 * that will be taken care of when the device is unbound from its driver.
1370 * If for some reason the resource needs to be released explicitly, because
1371 * of ordering issues for example, drivers must call devm_release_resource()
1372 * rather than the regular release_resource().
1373 *
1374 * When a conflict is detected between any existing resources and the newly
1375 * requested resource, an error message will be printed.
1376 *
1377 * Returns 0 on success or a negative error code on failure.
1378 */
1379int devm_request_resource(struct device *dev, struct resource *root,
1380 struct resource *new)
1381{
1382 struct resource *conflict, **ptr;
1383
1384 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1385 if (!ptr)
1386 return -ENOMEM;
1387
1388 *ptr = new;
1389
1390 conflict = request_resource_conflict(root, new);
1391 if (conflict) {
1392 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1393 new, conflict->name, conflict);
1394 devres_free(ptr);
1395 return -EBUSY;
1396 }
1397
1398 devres_add(dev, ptr);
1399 return 0;
1400}
1401EXPORT_SYMBOL(devm_request_resource);
1402
1403static int devm_resource_match(struct device *dev, void *res, void *data)
1404{
1405 struct resource **ptr = res;
1406
1407 return *ptr == data;
1408}
1409
1410/**
1411 * devm_release_resource() - release a previously requested resource
1412 * @dev: device for which to release the resource
1413 * @new: descriptor of the resource to release
1414 *
1415 * Releases a resource previously requested using devm_request_resource().
1416 */
1417void devm_release_resource(struct device *dev, struct resource *new)
1418{
1419 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1420 new));
1421}
1422EXPORT_SYMBOL(devm_release_resource);
1423
1424struct region_devres {
1425 struct resource *parent;
1426 resource_size_t start;
1427 resource_size_t n;
1428};
1429
1430static void devm_region_release(struct device *dev, void *res)
1431{
1432 struct region_devres *this = res;
1433
1434 __release_region(this->parent, this->start, this->n);
1435}
1436
1437static int devm_region_match(struct device *dev, void *res, void *match_data)
1438{
1439 struct region_devres *this = res, *match = match_data;
1440
1441 return this->parent == match->parent &&
1442 this->start == match->start && this->n == match->n;
1443}
1444
1445struct resource *
1446__devm_request_region(struct device *dev, struct resource *parent,
1447 resource_size_t start, resource_size_t n, const char *name)
1448{
1449 struct region_devres *dr = NULL;
1450 struct resource *res;
1451
1452 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1453 GFP_KERNEL);
1454 if (!dr)
1455 return NULL;
1456
1457 dr->parent = parent;
1458 dr->start = start;
1459 dr->n = n;
1460
1461 res = __request_region(parent, start, n, name, 0);
1462 if (res)
1463 devres_add(dev, dr);
1464 else
1465 devres_free(dr);
1466
1467 return res;
1468}
1469EXPORT_SYMBOL(__devm_request_region);
1470
1471void __devm_release_region(struct device *dev, struct resource *parent,
1472 resource_size_t start, resource_size_t n)
1473{
1474 struct region_devres match_data = { parent, start, n };
1475
1476 __release_region(parent, start, n);
1477 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1478 &match_data));
1479}
1480EXPORT_SYMBOL(__devm_release_region);
1481
1482/*
1483 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1484 */
1485#define MAXRESERVE 4
1486static int __init reserve_setup(char *str)
1487{
1488 static int reserved;
1489 static struct resource reserve[MAXRESERVE];
1490
1491 for (;;) {
1492 unsigned int io_start, io_num;
1493 int x = reserved;
1494 struct resource *parent;
1495
1496 if (get_option(&str, &io_start) != 2)
1497 break;
1498 if (get_option(&str, &io_num) == 0)
1499 break;
1500 if (x < MAXRESERVE) {
1501 struct resource *res = reserve + x;
1502
1503 /*
1504 * If the region starts below 0x10000, we assume it's
1505 * I/O port space; otherwise assume it's memory.
1506 */
1507 if (io_start < 0x10000) {
1508 res->flags = IORESOURCE_IO;
1509 parent = &ioport_resource;
1510 } else {
1511 res->flags = IORESOURCE_MEM;
1512 parent = &iomem_resource;
1513 }
1514 res->name = "reserved";
1515 res->start = io_start;
1516 res->end = io_start + io_num - 1;
1517 res->flags |= IORESOURCE_BUSY;
1518 res->desc = IORES_DESC_NONE;
1519 res->child = NULL;
1520 if (request_resource(parent, res) == 0)
1521 reserved = x+1;
1522 }
1523 }
1524 return 1;
1525}
1526__setup("reserve=", reserve_setup);
1527
1528/*
1529 * Check if the requested addr and size spans more than any slot in the
1530 * iomem resource tree.
1531 */
1532int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1533{
1534 struct resource *p = &iomem_resource;
1535 int err = 0;
1536 loff_t l;
1537
1538 read_lock(&resource_lock);
1539 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1540 /*
1541 * We can probably skip the resources without
1542 * IORESOURCE_IO attribute?
1543 */
1544 if (p->start >= addr + size)
1545 continue;
1546 if (p->end < addr)
1547 continue;
1548 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1549 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1550 continue;
1551 /*
1552 * if a resource is "BUSY", it's not a hardware resource
1553 * but a driver mapping of such a resource; we don't want
1554 * to warn for those; some drivers legitimately map only
1555 * partial hardware resources. (example: vesafb)
1556 */
1557 if (p->flags & IORESOURCE_BUSY)
1558 continue;
1559
1560 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1561 (unsigned long long)addr,
1562 (unsigned long long)(addr + size - 1),
1563 p->name, p);
1564 err = -1;
1565 break;
1566 }
1567 read_unlock(&resource_lock);
1568
1569 return err;
1570}
1571
1572#ifdef CONFIG_STRICT_DEVMEM
1573static int strict_iomem_checks = 1;
1574#else
1575static int strict_iomem_checks;
1576#endif
1577
1578/*
1579 * check if an address is reserved in the iomem resource tree
1580 * returns true if reserved, false if not reserved.
1581 */
1582bool iomem_is_exclusive(u64 addr)
1583{
1584 struct resource *p = &iomem_resource;
1585 bool err = false;
1586 loff_t l;
1587 int size = PAGE_SIZE;
1588
1589 if (!strict_iomem_checks)
1590 return false;
1591
1592 addr = addr & PAGE_MASK;
1593
1594 read_lock(&resource_lock);
1595 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1596 /*
1597 * We can probably skip the resources without
1598 * IORESOURCE_IO attribute?
1599 */
1600 if (p->start >= addr + size)
1601 break;
1602 if (p->end < addr)
1603 continue;
1604 /*
1605 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1606 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1607 * resource is busy.
1608 */
1609 if ((p->flags & IORESOURCE_BUSY) == 0)
1610 continue;
1611 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1612 || p->flags & IORESOURCE_EXCLUSIVE) {
1613 err = true;
1614 break;
1615 }
1616 }
1617 read_unlock(&resource_lock);
1618
1619 return err;
1620}
1621
1622struct resource_entry *resource_list_create_entry(struct resource *res,
1623 size_t extra_size)
1624{
1625 struct resource_entry *entry;
1626
1627 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1628 if (entry) {
1629 INIT_LIST_HEAD(&entry->node);
1630 entry->res = res ? res : &entry->__res;
1631 }
1632
1633 return entry;
1634}
1635EXPORT_SYMBOL(resource_list_create_entry);
1636
1637void resource_list_free(struct list_head *head)
1638{
1639 struct resource_entry *entry, *tmp;
1640
1641 list_for_each_entry_safe(entry, tmp, head, node)
1642 resource_list_destroy_entry(entry);
1643}
1644EXPORT_SYMBOL(resource_list_free);
1645
1646#ifdef CONFIG_DEVICE_PRIVATE
1647static struct resource *__request_free_mem_region(struct device *dev,
1648 struct resource *base, unsigned long size, const char *name)
1649{
1650 resource_size_t end, addr;
1651 struct resource *res;
1652
1653 size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
1654 end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
1655 addr = end - size + 1UL;
1656
1657 for (; addr > size && addr >= base->start; addr -= size) {
1658 if (region_intersects(addr, size, 0, IORES_DESC_NONE) !=
1659 REGION_DISJOINT)
1660 continue;
1661
1662 if (dev)
1663 res = devm_request_mem_region(dev, addr, size, name);
1664 else
1665 res = request_mem_region(addr, size, name);
1666 if (!res)
1667 return ERR_PTR(-ENOMEM);
1668 res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
1669 return res;
1670 }
1671
1672 return ERR_PTR(-ERANGE);
1673}
1674
1675/**
1676 * devm_request_free_mem_region - find free region for device private memory
1677 *
1678 * @dev: device struct to bind the resource to
1679 * @size: size in bytes of the device memory to add
1680 * @base: resource tree to look in
1681 *
1682 * This function tries to find an empty range of physical address big enough to
1683 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1684 * memory, which in turn allocates struct pages.
1685 */
1686struct resource *devm_request_free_mem_region(struct device *dev,
1687 struct resource *base, unsigned long size)
1688{
1689 return __request_free_mem_region(dev, base, size, dev_name(dev));
1690}
1691EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
1692
1693struct resource *request_free_mem_region(struct resource *base,
1694 unsigned long size, const char *name)
1695{
1696 return __request_free_mem_region(NULL, base, size, name);
1697}
1698EXPORT_SYMBOL_GPL(request_free_mem_region);
1699
1700#endif /* CONFIG_DEVICE_PRIVATE */
1701
1702static int __init strict_iomem(char *str)
1703{
1704 if (strstr(str, "relaxed"))
1705 strict_iomem_checks = 0;
1706 if (strstr(str, "strict"))
1707 strict_iomem_checks = 1;
1708 return 1;
1709}
1710
1711__setup("iomem=", strict_iomem);
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 <mj@ucw.cz>
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
51/* constraints to be met while allocating resources */
52struct resource_constraint {
53 resource_size_t min, max, align;
54 resource_size_t (*alignf)(void *, const struct resource *,
55 resource_size_t, resource_size_t);
56 void *alignf_data;
57};
58
59static DEFINE_RWLOCK(resource_lock);
60
61static struct resource *next_resource(struct resource *p, bool skip_children)
62{
63 if (!skip_children && p->child)
64 return p->child;
65 while (!p->sibling && p->parent)
66 p = p->parent;
67 return p->sibling;
68}
69
70#define for_each_resource(_root, _p, _skip_children) \
71 for ((_p) = (_root)->child; (_p); (_p) = next_resource(_p, _skip_children))
72
73#ifdef CONFIG_PROC_FS
74
75enum { MAX_IORES_LEVEL = 5 };
76
77static void *r_start(struct seq_file *m, loff_t *pos)
78 __acquires(resource_lock)
79{
80 struct resource *root = pde_data(file_inode(m->file));
81 struct resource *p;
82 loff_t l = *pos;
83
84 read_lock(&resource_lock);
85 for_each_resource(root, p, false) {
86 if (l-- == 0)
87 break;
88 }
89
90 return p;
91}
92
93static void *r_next(struct seq_file *m, void *v, loff_t *pos)
94{
95 struct resource *p = v;
96
97 (*pos)++;
98
99 return (void *)next_resource(p, false);
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 /**
156 * If the resource was allocated using memblock early during boot
157 * we'll leak it here: we can only return full pages back to the
158 * buddy and trying to be smart and reusing them eventually in
159 * alloc_resource() overcomplicates resource handling.
160 */
161 if (res && PageSlab(virt_to_head_page(res)))
162 kfree(res);
163}
164
165static struct resource *alloc_resource(gfp_t flags)
166{
167 return kzalloc(sizeof(struct resource), flags);
168}
169
170/* Return the conflict entry if you can't request it */
171static struct resource * __request_resource(struct resource *root, struct resource *new)
172{
173 resource_size_t start = new->start;
174 resource_size_t end = new->end;
175 struct resource *tmp, **p;
176
177 if (end < start)
178 return root;
179 if (start < root->start)
180 return root;
181 if (end > root->end)
182 return root;
183 p = &root->child;
184 for (;;) {
185 tmp = *p;
186 if (!tmp || tmp->start > end) {
187 new->sibling = tmp;
188 *p = new;
189 new->parent = root;
190 return NULL;
191 }
192 p = &tmp->sibling;
193 if (tmp->end < start)
194 continue;
195 return tmp;
196 }
197}
198
199static int __release_resource(struct resource *old, bool release_child)
200{
201 struct resource *tmp, **p, *chd;
202
203 p = &old->parent->child;
204 for (;;) {
205 tmp = *p;
206 if (!tmp)
207 break;
208 if (tmp == old) {
209 if (release_child || !(tmp->child)) {
210 *p = tmp->sibling;
211 } else {
212 for (chd = tmp->child;; chd = chd->sibling) {
213 chd->parent = tmp->parent;
214 if (!(chd->sibling))
215 break;
216 }
217 *p = tmp->child;
218 chd->sibling = tmp->sibling;
219 }
220 old->parent = NULL;
221 return 0;
222 }
223 p = &tmp->sibling;
224 }
225 return -EINVAL;
226}
227
228static void __release_child_resources(struct resource *r)
229{
230 struct resource *tmp, *p;
231 resource_size_t size;
232
233 p = r->child;
234 r->child = NULL;
235 while (p) {
236 tmp = p;
237 p = p->sibling;
238
239 tmp->parent = NULL;
240 tmp->sibling = NULL;
241 __release_child_resources(tmp);
242
243 printk(KERN_DEBUG "release child resource %pR\n", tmp);
244 /* need to restore size, and keep flags */
245 size = resource_size(tmp);
246 tmp->start = 0;
247 tmp->end = size - 1;
248 }
249}
250
251void release_child_resources(struct resource *r)
252{
253 write_lock(&resource_lock);
254 __release_child_resources(r);
255 write_unlock(&resource_lock);
256}
257
258/**
259 * request_resource_conflict - request and reserve an I/O or memory resource
260 * @root: root resource descriptor
261 * @new: resource descriptor desired by caller
262 *
263 * Returns 0 for success, conflict resource on error.
264 */
265struct resource *request_resource_conflict(struct resource *root, struct resource *new)
266{
267 struct resource *conflict;
268
269 write_lock(&resource_lock);
270 conflict = __request_resource(root, new);
271 write_unlock(&resource_lock);
272 return conflict;
273}
274
275/**
276 * request_resource - 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, negative error code on error.
281 */
282int request_resource(struct resource *root, struct resource *new)
283{
284 struct resource *conflict;
285
286 conflict = request_resource_conflict(root, new);
287 return conflict ? -EBUSY : 0;
288}
289
290EXPORT_SYMBOL(request_resource);
291
292/**
293 * release_resource - release a previously reserved resource
294 * @old: resource pointer
295 */
296int release_resource(struct resource *old)
297{
298 int retval;
299
300 write_lock(&resource_lock);
301 retval = __release_resource(old, true);
302 write_unlock(&resource_lock);
303 return retval;
304}
305
306EXPORT_SYMBOL(release_resource);
307
308/**
309 * find_next_iomem_res - Finds the lowest iomem resource that covers part of
310 * [@start..@end].
311 *
312 * If a resource is found, returns 0 and @*res is overwritten with the part
313 * of the resource that's within [@start..@end]; if none is found, returns
314 * -ENODEV. Returns -EINVAL for invalid parameters.
315 *
316 * @start: start address of the resource searched for
317 * @end: end address of same resource
318 * @flags: flags which the resource must have
319 * @desc: descriptor the resource must have
320 * @res: return ptr, if resource found
321 *
322 * The caller must specify @start, @end, @flags, and @desc
323 * (which may be IORES_DESC_NONE).
324 */
325static int find_next_iomem_res(resource_size_t start, resource_size_t end,
326 unsigned long flags, unsigned long desc,
327 struct resource *res)
328{
329 struct resource *p;
330
331 if (!res)
332 return -EINVAL;
333
334 if (start >= end)
335 return -EINVAL;
336
337 read_lock(&resource_lock);
338
339 for_each_resource(&iomem_resource, p, false) {
340 /* If we passed the resource we are looking for, stop */
341 if (p->start > end) {
342 p = NULL;
343 break;
344 }
345
346 /* Skip until we find a range that matches what we look for */
347 if (p->end < start)
348 continue;
349
350 if ((p->flags & flags) != flags)
351 continue;
352 if ((desc != IORES_DESC_NONE) && (desc != p->desc))
353 continue;
354
355 /* Found a match, break */
356 break;
357 }
358
359 if (p) {
360 /* copy data */
361 *res = (struct resource) {
362 .start = max(start, p->start),
363 .end = min(end, p->end),
364 .flags = p->flags,
365 .desc = p->desc,
366 .parent = p->parent,
367 };
368 }
369
370 read_unlock(&resource_lock);
371 return p ? 0 : -ENODEV;
372}
373
374static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
375 unsigned long flags, unsigned long desc,
376 void *arg,
377 int (*func)(struct resource *, void *))
378{
379 struct resource res;
380 int ret = -EINVAL;
381
382 while (start < end &&
383 !find_next_iomem_res(start, end, flags, desc, &res)) {
384 ret = (*func)(&res, arg);
385 if (ret)
386 break;
387
388 start = res.end + 1;
389 }
390
391 return ret;
392}
393
394/**
395 * walk_iomem_res_desc - Walks through iomem resources and calls func()
396 * with matching resource ranges.
397 * *
398 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
399 * @flags: I/O resource flags
400 * @start: start addr
401 * @end: end addr
402 * @arg: function argument for the callback @func
403 * @func: callback function that is called for each qualifying resource area
404 *
405 * All the memory ranges which overlap start,end and also match flags and
406 * desc are valid candidates.
407 *
408 * NOTE: For a new descriptor search, define a new IORES_DESC in
409 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
410 */
411int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
412 u64 end, void *arg, int (*func)(struct resource *, void *))
413{
414 return __walk_iomem_res_desc(start, end, flags, desc, arg, func);
415}
416EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
417
418/*
419 * This function calls the @func callback against all memory ranges of type
420 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
421 * Now, this function is only for System RAM, it deals with full ranges and
422 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
423 * ranges.
424 */
425int walk_system_ram_res(u64 start, u64 end, void *arg,
426 int (*func)(struct resource *, void *))
427{
428 unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
429
430 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
431 func);
432}
433
434/*
435 * This function, being a variant of walk_system_ram_res(), calls the @func
436 * callback against all memory ranges of type System RAM which are marked as
437 * IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY in reversed order, i.e., from
438 * higher to lower.
439 */
440int walk_system_ram_res_rev(u64 start, u64 end, void *arg,
441 int (*func)(struct resource *, void *))
442{
443 struct resource res, *rams;
444 int rams_size = 16, i;
445 unsigned long flags;
446 int ret = -1;
447
448 /* create a list */
449 rams = kvcalloc(rams_size, sizeof(struct resource), GFP_KERNEL);
450 if (!rams)
451 return ret;
452
453 flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
454 i = 0;
455 while ((start < end) &&
456 (!find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res))) {
457 if (i >= rams_size) {
458 /* re-alloc */
459 struct resource *rams_new;
460
461 rams_new = kvrealloc(rams, rams_size * sizeof(struct resource),
462 (rams_size + 16) * sizeof(struct resource),
463 GFP_KERNEL);
464 if (!rams_new)
465 goto out;
466
467 rams = rams_new;
468 rams_size += 16;
469 }
470
471 rams[i].start = res.start;
472 rams[i++].end = res.end;
473
474 start = res.end + 1;
475 }
476
477 /* go reverse */
478 for (i--; i >= 0; i--) {
479 ret = (*func)(&rams[i], arg);
480 if (ret)
481 break;
482 }
483
484out:
485 kvfree(rams);
486 return ret;
487}
488
489/*
490 * This function calls the @func callback against all memory ranges, which
491 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
492 */
493int walk_mem_res(u64 start, u64 end, void *arg,
494 int (*func)(struct resource *, void *))
495{
496 unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
497
498 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
499 func);
500}
501
502/*
503 * This function calls the @func callback against all memory ranges of type
504 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
505 * It is to be used only for System RAM.
506 */
507int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
508 void *arg, int (*func)(unsigned long, unsigned long, void *))
509{
510 resource_size_t start, end;
511 unsigned long flags;
512 struct resource res;
513 unsigned long pfn, end_pfn;
514 int ret = -EINVAL;
515
516 start = (u64) start_pfn << PAGE_SHIFT;
517 end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
518 flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
519 while (start < end &&
520 !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res)) {
521 pfn = PFN_UP(res.start);
522 end_pfn = PFN_DOWN(res.end + 1);
523 if (end_pfn > pfn)
524 ret = (*func)(pfn, end_pfn - pfn, arg);
525 if (ret)
526 break;
527 start = res.end + 1;
528 }
529 return ret;
530}
531
532static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
533{
534 return 1;
535}
536
537/*
538 * This generic page_is_ram() returns true if specified address is
539 * registered as System RAM in iomem_resource list.
540 */
541int __weak page_is_ram(unsigned long pfn)
542{
543 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
544}
545EXPORT_SYMBOL_GPL(page_is_ram);
546
547static int __region_intersects(struct resource *parent, resource_size_t start,
548 size_t size, unsigned long flags,
549 unsigned long desc)
550{
551 struct resource res;
552 int type = 0; int other = 0;
553 struct resource *p;
554
555 res.start = start;
556 res.end = start + size - 1;
557
558 for (p = parent->child; p ; p = p->sibling) {
559 bool is_type = (((p->flags & flags) == flags) &&
560 ((desc == IORES_DESC_NONE) ||
561 (desc == p->desc)));
562
563 if (resource_overlaps(p, &res))
564 is_type ? type++ : other++;
565 }
566
567 if (type == 0)
568 return REGION_DISJOINT;
569
570 if (other == 0)
571 return REGION_INTERSECTS;
572
573 return REGION_MIXED;
574}
575
576/**
577 * region_intersects() - determine intersection of region with known resources
578 * @start: region start address
579 * @size: size of region
580 * @flags: flags of resource (in iomem_resource)
581 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
582 *
583 * Check if the specified region partially overlaps or fully eclipses a
584 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
585 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
586 * return REGION_MIXED if the region overlaps @flags/@desc and another
587 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
588 * and no other defined resource. Note that REGION_INTERSECTS is also
589 * returned in the case when the specified region overlaps RAM and undefined
590 * memory holes.
591 *
592 * region_intersect() is used by memory remapping functions to ensure
593 * the user is not remapping RAM and is a vast speed up over walking
594 * through the resource table page by page.
595 */
596int region_intersects(resource_size_t start, size_t size, unsigned long flags,
597 unsigned long desc)
598{
599 int ret;
600
601 read_lock(&resource_lock);
602 ret = __region_intersects(&iomem_resource, start, size, flags, desc);
603 read_unlock(&resource_lock);
604
605 return ret;
606}
607EXPORT_SYMBOL_GPL(region_intersects);
608
609void __weak arch_remove_reservations(struct resource *avail)
610{
611}
612
613static resource_size_t simple_align_resource(void *data,
614 const struct resource *avail,
615 resource_size_t size,
616 resource_size_t align)
617{
618 return avail->start;
619}
620
621static void resource_clip(struct resource *res, resource_size_t min,
622 resource_size_t max)
623{
624 if (res->start < min)
625 res->start = min;
626 if (res->end > max)
627 res->end = max;
628}
629
630/*
631 * Find empty slot in the resource tree with the given range and
632 * alignment constraints
633 */
634static int __find_resource(struct resource *root, struct resource *old,
635 struct resource *new,
636 resource_size_t size,
637 struct resource_constraint *constraint)
638{
639 struct resource *this = root->child;
640 struct resource tmp = *new, avail, alloc;
641
642 tmp.start = root->start;
643 /*
644 * Skip past an allocated resource that starts at 0, since the assignment
645 * of this->start - 1 to tmp->end below would cause an underflow.
646 */
647 if (this && this->start == root->start) {
648 tmp.start = (this == old) ? old->start : this->end + 1;
649 this = this->sibling;
650 }
651 for(;;) {
652 if (this)
653 tmp.end = (this == old) ? this->end : this->start - 1;
654 else
655 tmp.end = root->end;
656
657 if (tmp.end < tmp.start)
658 goto next;
659
660 resource_clip(&tmp, constraint->min, constraint->max);
661 arch_remove_reservations(&tmp);
662
663 /* Check for overflow after ALIGN() */
664 avail.start = ALIGN(tmp.start, constraint->align);
665 avail.end = tmp.end;
666 avail.flags = new->flags & ~IORESOURCE_UNSET;
667 if (avail.start >= tmp.start) {
668 alloc.flags = avail.flags;
669 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
670 size, constraint->align);
671 alloc.end = alloc.start + size - 1;
672 if (alloc.start <= alloc.end &&
673 resource_contains(&avail, &alloc)) {
674 new->start = alloc.start;
675 new->end = alloc.end;
676 return 0;
677 }
678 }
679
680next: if (!this || this->end == root->end)
681 break;
682
683 if (this != old)
684 tmp.start = this->end + 1;
685 this = this->sibling;
686 }
687 return -EBUSY;
688}
689
690/*
691 * Find empty slot in the resource tree given range and alignment.
692 */
693static int find_resource(struct resource *root, struct resource *new,
694 resource_size_t size,
695 struct resource_constraint *constraint)
696{
697 return __find_resource(root, NULL, new, size, constraint);
698}
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(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_size_t (*alignf)(void *,
765 const struct resource *,
766 resource_size_t,
767 resource_size_t),
768 void *alignf_data)
769{
770 int err;
771 struct resource_constraint constraint;
772
773 if (!alignf)
774 alignf = simple_align_resource;
775
776 constraint.min = min;
777 constraint.max = max;
778 constraint.align = align;
779 constraint.alignf = alignf;
780 constraint.alignf_data = alignf_data;
781
782 if ( new->parent ) {
783 /* resource is already allocated, try reallocating with
784 the new constraints */
785 return reallocate_resource(root, new, size, &constraint);
786 }
787
788 write_lock(&resource_lock);
789 err = find_resource(root, new, size, &constraint);
790 if (err >= 0 && __request_resource(root, new))
791 err = -EBUSY;
792 write_unlock(&resource_lock);
793 return err;
794}
795
796EXPORT_SYMBOL(allocate_resource);
797
798/**
799 * lookup_resource - find an existing resource by a resource start address
800 * @root: root resource descriptor
801 * @start: resource start address
802 *
803 * Returns a pointer to the resource if found, NULL otherwise
804 */
805struct resource *lookup_resource(struct resource *root, resource_size_t start)
806{
807 struct resource *res;
808
809 read_lock(&resource_lock);
810 for (res = root->child; res; res = res->sibling) {
811 if (res->start == start)
812 break;
813 }
814 read_unlock(&resource_lock);
815
816 return res;
817}
818
819/*
820 * Insert a resource into the resource tree. If successful, return NULL,
821 * otherwise return the conflicting resource (compare to __request_resource())
822 */
823static struct resource * __insert_resource(struct resource *parent, struct resource *new)
824{
825 struct resource *first, *next;
826
827 for (;; parent = first) {
828 first = __request_resource(parent, new);
829 if (!first)
830 return first;
831
832 if (first == parent)
833 return first;
834 if (WARN_ON(first == new)) /* duplicated insertion */
835 return first;
836
837 if ((first->start > new->start) || (first->end < new->end))
838 break;
839 if ((first->start == new->start) && (first->end == new->end))
840 break;
841 }
842
843 for (next = first; ; next = next->sibling) {
844 /* Partial overlap? Bad, and unfixable */
845 if (next->start < new->start || next->end > new->end)
846 return next;
847 if (!next->sibling)
848 break;
849 if (next->sibling->start > new->end)
850 break;
851 }
852
853 new->parent = parent;
854 new->sibling = next->sibling;
855 new->child = first;
856
857 next->sibling = NULL;
858 for (next = first; next; next = next->sibling)
859 next->parent = new;
860
861 if (parent->child == first) {
862 parent->child = new;
863 } else {
864 next = parent->child;
865 while (next->sibling != first)
866 next = next->sibling;
867 next->sibling = new;
868 }
869 return NULL;
870}
871
872/**
873 * insert_resource_conflict - Inserts resource in the resource tree
874 * @parent: parent of the new resource
875 * @new: new resource to insert
876 *
877 * Returns 0 on success, conflict resource if the resource can't be inserted.
878 *
879 * This function is equivalent to request_resource_conflict when no conflict
880 * happens. If a conflict happens, and the conflicting resources
881 * entirely fit within the range of the new resource, then the new
882 * resource is inserted and the conflicting resources become children of
883 * the new resource.
884 *
885 * This function is intended for producers of resources, such as FW modules
886 * and bus drivers.
887 */
888struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
889{
890 struct resource *conflict;
891
892 write_lock(&resource_lock);
893 conflict = __insert_resource(parent, new);
894 write_unlock(&resource_lock);
895 return conflict;
896}
897
898/**
899 * insert_resource - Inserts a resource in the resource tree
900 * @parent: parent of the new resource
901 * @new: new resource to insert
902 *
903 * Returns 0 on success, -EBUSY if the resource can't be inserted.
904 *
905 * This function is intended for producers of resources, such as FW modules
906 * and bus drivers.
907 */
908int insert_resource(struct resource *parent, struct resource *new)
909{
910 struct resource *conflict;
911
912 conflict = insert_resource_conflict(parent, new);
913 return conflict ? -EBUSY : 0;
914}
915EXPORT_SYMBOL_GPL(insert_resource);
916
917/**
918 * insert_resource_expand_to_fit - Insert a resource into the resource tree
919 * @root: root resource descriptor
920 * @new: new resource to insert
921 *
922 * Insert a resource into the resource tree, possibly expanding it in order
923 * to make it encompass any conflicting resources.
924 */
925void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
926{
927 if (new->parent)
928 return;
929
930 write_lock(&resource_lock);
931 for (;;) {
932 struct resource *conflict;
933
934 conflict = __insert_resource(root, new);
935 if (!conflict)
936 break;
937 if (conflict == root)
938 break;
939
940 /* Ok, expand resource to cover the conflict, then try again .. */
941 if (conflict->start < new->start)
942 new->start = conflict->start;
943 if (conflict->end > new->end)
944 new->end = conflict->end;
945
946 pr_info("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
947 }
948 write_unlock(&resource_lock);
949}
950/*
951 * Not for general consumption, only early boot memory map parsing, PCI
952 * resource discovery, and late discovery of CXL resources are expected
953 * to use this interface. The former are built-in and only the latter,
954 * CXL, is a module.
955 */
956EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit, CXL);
957
958/**
959 * remove_resource - Remove a resource in the resource tree
960 * @old: resource to remove
961 *
962 * Returns 0 on success, -EINVAL if the resource is not valid.
963 *
964 * This function removes a resource previously inserted by insert_resource()
965 * or insert_resource_conflict(), and moves the children (if any) up to
966 * where they were before. insert_resource() and insert_resource_conflict()
967 * insert a new resource, and move any conflicting resources down to the
968 * children of the new resource.
969 *
970 * insert_resource(), insert_resource_conflict() and remove_resource() are
971 * intended for producers of resources, such as FW modules and bus drivers.
972 */
973int remove_resource(struct resource *old)
974{
975 int retval;
976
977 write_lock(&resource_lock);
978 retval = __release_resource(old, false);
979 write_unlock(&resource_lock);
980 return retval;
981}
982EXPORT_SYMBOL_GPL(remove_resource);
983
984static int __adjust_resource(struct resource *res, resource_size_t start,
985 resource_size_t size)
986{
987 struct resource *tmp, *parent = res->parent;
988 resource_size_t end = start + size - 1;
989 int result = -EBUSY;
990
991 if (!parent)
992 goto skip;
993
994 if ((start < parent->start) || (end > parent->end))
995 goto out;
996
997 if (res->sibling && (res->sibling->start <= end))
998 goto out;
999
1000 tmp = parent->child;
1001 if (tmp != res) {
1002 while (tmp->sibling != res)
1003 tmp = tmp->sibling;
1004 if (start <= tmp->end)
1005 goto out;
1006 }
1007
1008skip:
1009 for (tmp = res->child; tmp; tmp = tmp->sibling)
1010 if ((tmp->start < start) || (tmp->end > end))
1011 goto out;
1012
1013 res->start = start;
1014 res->end = end;
1015 result = 0;
1016
1017 out:
1018 return result;
1019}
1020
1021/**
1022 * adjust_resource - modify a resource's start and size
1023 * @res: resource to modify
1024 * @start: new start value
1025 * @size: new size
1026 *
1027 * Given an existing resource, change its start and size to match the
1028 * arguments. Returns 0 on success, -EBUSY if it can't fit.
1029 * Existing children of the resource are assumed to be immutable.
1030 */
1031int adjust_resource(struct resource *res, resource_size_t start,
1032 resource_size_t size)
1033{
1034 int result;
1035
1036 write_lock(&resource_lock);
1037 result = __adjust_resource(res, start, size);
1038 write_unlock(&resource_lock);
1039 return result;
1040}
1041EXPORT_SYMBOL(adjust_resource);
1042
1043static void __init
1044__reserve_region_with_split(struct resource *root, resource_size_t start,
1045 resource_size_t end, const char *name)
1046{
1047 struct resource *parent = root;
1048 struct resource *conflict;
1049 struct resource *res = alloc_resource(GFP_ATOMIC);
1050 struct resource *next_res = NULL;
1051 int type = resource_type(root);
1052
1053 if (!res)
1054 return;
1055
1056 res->name = name;
1057 res->start = start;
1058 res->end = end;
1059 res->flags = type | IORESOURCE_BUSY;
1060 res->desc = IORES_DESC_NONE;
1061
1062 while (1) {
1063
1064 conflict = __request_resource(parent, res);
1065 if (!conflict) {
1066 if (!next_res)
1067 break;
1068 res = next_res;
1069 next_res = NULL;
1070 continue;
1071 }
1072
1073 /* conflict covered whole area */
1074 if (conflict->start <= res->start &&
1075 conflict->end >= res->end) {
1076 free_resource(res);
1077 WARN_ON(next_res);
1078 break;
1079 }
1080
1081 /* failed, split and try again */
1082 if (conflict->start > res->start) {
1083 end = res->end;
1084 res->end = conflict->start - 1;
1085 if (conflict->end < end) {
1086 next_res = alloc_resource(GFP_ATOMIC);
1087 if (!next_res) {
1088 free_resource(res);
1089 break;
1090 }
1091 next_res->name = name;
1092 next_res->start = conflict->end + 1;
1093 next_res->end = end;
1094 next_res->flags = type | IORESOURCE_BUSY;
1095 next_res->desc = IORES_DESC_NONE;
1096 }
1097 } else {
1098 res->start = conflict->end + 1;
1099 }
1100 }
1101
1102}
1103
1104void __init
1105reserve_region_with_split(struct resource *root, resource_size_t start,
1106 resource_size_t end, const char *name)
1107{
1108 int abort = 0;
1109
1110 write_lock(&resource_lock);
1111 if (root->start > start || root->end < end) {
1112 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1113 (unsigned long long)start, (unsigned long long)end,
1114 root);
1115 if (start > root->end || end < root->start)
1116 abort = 1;
1117 else {
1118 if (end > root->end)
1119 end = root->end;
1120 if (start < root->start)
1121 start = root->start;
1122 pr_err("fixing request to [0x%llx-0x%llx]\n",
1123 (unsigned long long)start,
1124 (unsigned long long)end);
1125 }
1126 dump_stack();
1127 }
1128 if (!abort)
1129 __reserve_region_with_split(root, start, end, name);
1130 write_unlock(&resource_lock);
1131}
1132
1133/**
1134 * resource_alignment - calculate resource's alignment
1135 * @res: resource pointer
1136 *
1137 * Returns alignment on success, 0 (invalid alignment) on failure.
1138 */
1139resource_size_t resource_alignment(struct resource *res)
1140{
1141 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1142 case IORESOURCE_SIZEALIGN:
1143 return resource_size(res);
1144 case IORESOURCE_STARTALIGN:
1145 return res->start;
1146 default:
1147 return 0;
1148 }
1149}
1150
1151/*
1152 * This is compatibility stuff for IO resources.
1153 *
1154 * Note how this, unlike the above, knows about
1155 * the IO flag meanings (busy etc).
1156 *
1157 * request_region creates a new busy region.
1158 *
1159 * release_region releases a matching busy region.
1160 */
1161
1162static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1163
1164static struct inode *iomem_inode;
1165
1166#ifdef CONFIG_IO_STRICT_DEVMEM
1167static void revoke_iomem(struct resource *res)
1168{
1169 /* pairs with smp_store_release() in iomem_init_inode() */
1170 struct inode *inode = smp_load_acquire(&iomem_inode);
1171
1172 /*
1173 * Check that the initialization has completed. Losing the race
1174 * is ok because it means drivers are claiming resources before
1175 * the fs_initcall level of init and prevent iomem_get_mapping users
1176 * from establishing mappings.
1177 */
1178 if (!inode)
1179 return;
1180
1181 /*
1182 * The expectation is that the driver has successfully marked
1183 * the resource busy by this point, so devmem_is_allowed()
1184 * should start returning false, however for performance this
1185 * does not iterate the entire resource range.
1186 */
1187 if (devmem_is_allowed(PHYS_PFN(res->start)) &&
1188 devmem_is_allowed(PHYS_PFN(res->end))) {
1189 /*
1190 * *cringe* iomem=relaxed says "go ahead, what's the
1191 * worst that can happen?"
1192 */
1193 return;
1194 }
1195
1196 unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1);
1197}
1198#else
1199static void revoke_iomem(struct resource *res) {}
1200#endif
1201
1202struct address_space *iomem_get_mapping(void)
1203{
1204 /*
1205 * This function is only called from file open paths, hence guaranteed
1206 * that fs_initcalls have completed and no need to check for NULL. But
1207 * since revoke_iomem can be called before the initcall we still need
1208 * the barrier to appease checkers.
1209 */
1210 return smp_load_acquire(&iomem_inode)->i_mapping;
1211}
1212
1213static int __request_region_locked(struct resource *res, struct resource *parent,
1214 resource_size_t start, resource_size_t n,
1215 const char *name, int flags)
1216{
1217 DECLARE_WAITQUEUE(wait, current);
1218
1219 res->name = name;
1220 res->start = start;
1221 res->end = start + n - 1;
1222
1223 for (;;) {
1224 struct resource *conflict;
1225
1226 res->flags = resource_type(parent) | resource_ext_type(parent);
1227 res->flags |= IORESOURCE_BUSY | flags;
1228 res->desc = parent->desc;
1229
1230 conflict = __request_resource(parent, res);
1231 if (!conflict)
1232 break;
1233 /*
1234 * mm/hmm.c reserves physical addresses which then
1235 * become unavailable to other users. Conflicts are
1236 * not expected. Warn to aid debugging if encountered.
1237 */
1238 if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1239 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1240 conflict->name, conflict, res);
1241 }
1242 if (conflict != parent) {
1243 if (!(conflict->flags & IORESOURCE_BUSY)) {
1244 parent = conflict;
1245 continue;
1246 }
1247 }
1248 if (conflict->flags & flags & IORESOURCE_MUXED) {
1249 add_wait_queue(&muxed_resource_wait, &wait);
1250 write_unlock(&resource_lock);
1251 set_current_state(TASK_UNINTERRUPTIBLE);
1252 schedule();
1253 remove_wait_queue(&muxed_resource_wait, &wait);
1254 write_lock(&resource_lock);
1255 continue;
1256 }
1257 /* Uhhuh, that didn't work out.. */
1258 return -EBUSY;
1259 }
1260
1261 return 0;
1262}
1263
1264/**
1265 * __request_region - create a new busy resource region
1266 * @parent: parent resource descriptor
1267 * @start: resource start address
1268 * @n: resource region size
1269 * @name: reserving caller's ID string
1270 * @flags: IO resource flags
1271 */
1272struct resource *__request_region(struct resource *parent,
1273 resource_size_t start, resource_size_t n,
1274 const char *name, int flags)
1275{
1276 struct resource *res = alloc_resource(GFP_KERNEL);
1277 int ret;
1278
1279 if (!res)
1280 return NULL;
1281
1282 write_lock(&resource_lock);
1283 ret = __request_region_locked(res, parent, start, n, name, flags);
1284 write_unlock(&resource_lock);
1285
1286 if (ret) {
1287 free_resource(res);
1288 return NULL;
1289 }
1290
1291 if (parent == &iomem_resource)
1292 revoke_iomem(res);
1293
1294 return res;
1295}
1296EXPORT_SYMBOL(__request_region);
1297
1298/**
1299 * __release_region - release a previously reserved resource region
1300 * @parent: parent resource descriptor
1301 * @start: resource start address
1302 * @n: resource region size
1303 *
1304 * The described resource region must match a currently busy region.
1305 */
1306void __release_region(struct resource *parent, resource_size_t start,
1307 resource_size_t n)
1308{
1309 struct resource **p;
1310 resource_size_t end;
1311
1312 p = &parent->child;
1313 end = start + n - 1;
1314
1315 write_lock(&resource_lock);
1316
1317 for (;;) {
1318 struct resource *res = *p;
1319
1320 if (!res)
1321 break;
1322 if (res->start <= start && res->end >= end) {
1323 if (!(res->flags & IORESOURCE_BUSY)) {
1324 p = &res->child;
1325 continue;
1326 }
1327 if (res->start != start || res->end != end)
1328 break;
1329 *p = res->sibling;
1330 write_unlock(&resource_lock);
1331 if (res->flags & IORESOURCE_MUXED)
1332 wake_up(&muxed_resource_wait);
1333 free_resource(res);
1334 return;
1335 }
1336 p = &res->sibling;
1337 }
1338
1339 write_unlock(&resource_lock);
1340
1341 pr_warn("Trying to free nonexistent resource <%pa-%pa>\n", &start, &end);
1342}
1343EXPORT_SYMBOL(__release_region);
1344
1345#ifdef CONFIG_MEMORY_HOTREMOVE
1346/**
1347 * release_mem_region_adjustable - release a previously reserved memory region
1348 * @start: resource start address
1349 * @size: resource region size
1350 *
1351 * This interface is intended for memory hot-delete. The requested region
1352 * is released from a currently busy memory resource. The requested region
1353 * must either match exactly or fit into a single busy resource entry. In
1354 * the latter case, the remaining resource is adjusted accordingly.
1355 * Existing children of the busy memory resource must be immutable in the
1356 * request.
1357 *
1358 * Note:
1359 * - Additional release conditions, such as overlapping region, can be
1360 * supported after they are confirmed as valid cases.
1361 * - When a busy memory resource gets split into two entries, the code
1362 * assumes that all children remain in the lower address entry for
1363 * simplicity. Enhance this logic when necessary.
1364 */
1365void release_mem_region_adjustable(resource_size_t start, resource_size_t size)
1366{
1367 struct resource *parent = &iomem_resource;
1368 struct resource *new_res = NULL;
1369 bool alloc_nofail = false;
1370 struct resource **p;
1371 struct resource *res;
1372 resource_size_t end;
1373
1374 end = start + size - 1;
1375 if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
1376 return;
1377
1378 /*
1379 * We free up quite a lot of memory on memory hotunplug (esp., memap),
1380 * just before releasing the region. This is highly unlikely to
1381 * fail - let's play save and make it never fail as the caller cannot
1382 * perform any error handling (e.g., trying to re-add memory will fail
1383 * similarly).
1384 */
1385retry:
1386 new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
1387
1388 p = &parent->child;
1389 write_lock(&resource_lock);
1390
1391 while ((res = *p)) {
1392 if (res->start >= end)
1393 break;
1394
1395 /* look for the next resource if it does not fit into */
1396 if (res->start > start || res->end < end) {
1397 p = &res->sibling;
1398 continue;
1399 }
1400
1401 if (!(res->flags & IORESOURCE_MEM))
1402 break;
1403
1404 if (!(res->flags & IORESOURCE_BUSY)) {
1405 p = &res->child;
1406 continue;
1407 }
1408
1409 /* found the target resource; let's adjust accordingly */
1410 if (res->start == start && res->end == end) {
1411 /* free the whole entry */
1412 *p = res->sibling;
1413 free_resource(res);
1414 } else if (res->start == start && res->end != end) {
1415 /* adjust the start */
1416 WARN_ON_ONCE(__adjust_resource(res, end + 1,
1417 res->end - end));
1418 } else if (res->start != start && res->end == end) {
1419 /* adjust the end */
1420 WARN_ON_ONCE(__adjust_resource(res, res->start,
1421 start - res->start));
1422 } else {
1423 /* split into two entries - we need a new resource */
1424 if (!new_res) {
1425 new_res = alloc_resource(GFP_ATOMIC);
1426 if (!new_res) {
1427 alloc_nofail = true;
1428 write_unlock(&resource_lock);
1429 goto retry;
1430 }
1431 }
1432 new_res->name = res->name;
1433 new_res->start = end + 1;
1434 new_res->end = res->end;
1435 new_res->flags = res->flags;
1436 new_res->desc = res->desc;
1437 new_res->parent = res->parent;
1438 new_res->sibling = res->sibling;
1439 new_res->child = NULL;
1440
1441 if (WARN_ON_ONCE(__adjust_resource(res, res->start,
1442 start - res->start)))
1443 break;
1444 res->sibling = new_res;
1445 new_res = NULL;
1446 }
1447
1448 break;
1449 }
1450
1451 write_unlock(&resource_lock);
1452 free_resource(new_res);
1453}
1454#endif /* CONFIG_MEMORY_HOTREMOVE */
1455
1456#ifdef CONFIG_MEMORY_HOTPLUG
1457static bool system_ram_resources_mergeable(struct resource *r1,
1458 struct resource *r2)
1459{
1460 /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1461 return r1->flags == r2->flags && r1->end + 1 == r2->start &&
1462 r1->name == r2->name && r1->desc == r2->desc &&
1463 !r1->child && !r2->child;
1464}
1465
1466/**
1467 * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1468 * merge it with adjacent, mergeable resources
1469 * @res: resource descriptor
1470 *
1471 * This interface is intended for memory hotplug, whereby lots of contiguous
1472 * system ram resources are added (e.g., via add_memory*()) by a driver, and
1473 * the actual resource boundaries are not of interest (e.g., it might be
1474 * relevant for DIMMs). Only resources that are marked mergeable, that have the
1475 * same parent, and that don't have any children are considered. All mergeable
1476 * resources must be immutable during the request.
1477 *
1478 * Note:
1479 * - The caller has to make sure that no pointers to resources that are
1480 * marked mergeable are used anymore after this call - the resource might
1481 * be freed and the pointer might be stale!
1482 * - release_mem_region_adjustable() will split on demand on memory hotunplug
1483 */
1484void merge_system_ram_resource(struct resource *res)
1485{
1486 const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
1487 struct resource *cur;
1488
1489 if (WARN_ON_ONCE((res->flags & flags) != flags))
1490 return;
1491
1492 write_lock(&resource_lock);
1493 res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
1494
1495 /* Try to merge with next item in the list. */
1496 cur = res->sibling;
1497 if (cur && system_ram_resources_mergeable(res, cur)) {
1498 res->end = cur->end;
1499 res->sibling = cur->sibling;
1500 free_resource(cur);
1501 }
1502
1503 /* Try to merge with previous item in the list. */
1504 cur = res->parent->child;
1505 while (cur && cur->sibling != res)
1506 cur = cur->sibling;
1507 if (cur && system_ram_resources_mergeable(cur, res)) {
1508 cur->end = res->end;
1509 cur->sibling = res->sibling;
1510 free_resource(res);
1511 }
1512 write_unlock(&resource_lock);
1513}
1514#endif /* CONFIG_MEMORY_HOTPLUG */
1515
1516/*
1517 * Managed region resource
1518 */
1519static void devm_resource_release(struct device *dev, void *ptr)
1520{
1521 struct resource **r = ptr;
1522
1523 release_resource(*r);
1524}
1525
1526/**
1527 * devm_request_resource() - request and reserve an I/O or memory resource
1528 * @dev: device for which to request the resource
1529 * @root: root of the resource tree from which to request the resource
1530 * @new: descriptor of the resource to request
1531 *
1532 * This is a device-managed version of request_resource(). There is usually
1533 * no need to release resources requested by this function explicitly since
1534 * that will be taken care of when the device is unbound from its driver.
1535 * If for some reason the resource needs to be released explicitly, because
1536 * of ordering issues for example, drivers must call devm_release_resource()
1537 * rather than the regular release_resource().
1538 *
1539 * When a conflict is detected between any existing resources and the newly
1540 * requested resource, an error message will be printed.
1541 *
1542 * Returns 0 on success or a negative error code on failure.
1543 */
1544int devm_request_resource(struct device *dev, struct resource *root,
1545 struct resource *new)
1546{
1547 struct resource *conflict, **ptr;
1548
1549 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1550 if (!ptr)
1551 return -ENOMEM;
1552
1553 *ptr = new;
1554
1555 conflict = request_resource_conflict(root, new);
1556 if (conflict) {
1557 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1558 new, conflict->name, conflict);
1559 devres_free(ptr);
1560 return -EBUSY;
1561 }
1562
1563 devres_add(dev, ptr);
1564 return 0;
1565}
1566EXPORT_SYMBOL(devm_request_resource);
1567
1568static int devm_resource_match(struct device *dev, void *res, void *data)
1569{
1570 struct resource **ptr = res;
1571
1572 return *ptr == data;
1573}
1574
1575/**
1576 * devm_release_resource() - release a previously requested resource
1577 * @dev: device for which to release the resource
1578 * @new: descriptor of the resource to release
1579 *
1580 * Releases a resource previously requested using devm_request_resource().
1581 */
1582void devm_release_resource(struct device *dev, struct resource *new)
1583{
1584 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1585 new));
1586}
1587EXPORT_SYMBOL(devm_release_resource);
1588
1589struct region_devres {
1590 struct resource *parent;
1591 resource_size_t start;
1592 resource_size_t n;
1593};
1594
1595static void devm_region_release(struct device *dev, void *res)
1596{
1597 struct region_devres *this = res;
1598
1599 __release_region(this->parent, this->start, this->n);
1600}
1601
1602static int devm_region_match(struct device *dev, void *res, void *match_data)
1603{
1604 struct region_devres *this = res, *match = match_data;
1605
1606 return this->parent == match->parent &&
1607 this->start == match->start && this->n == match->n;
1608}
1609
1610struct resource *
1611__devm_request_region(struct device *dev, struct resource *parent,
1612 resource_size_t start, resource_size_t n, const char *name)
1613{
1614 struct region_devres *dr = NULL;
1615 struct resource *res;
1616
1617 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1618 GFP_KERNEL);
1619 if (!dr)
1620 return NULL;
1621
1622 dr->parent = parent;
1623 dr->start = start;
1624 dr->n = n;
1625
1626 res = __request_region(parent, start, n, name, 0);
1627 if (res)
1628 devres_add(dev, dr);
1629 else
1630 devres_free(dr);
1631
1632 return res;
1633}
1634EXPORT_SYMBOL(__devm_request_region);
1635
1636void __devm_release_region(struct device *dev, struct resource *parent,
1637 resource_size_t start, resource_size_t n)
1638{
1639 struct region_devres match_data = { parent, start, n };
1640
1641 __release_region(parent, start, n);
1642 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1643 &match_data));
1644}
1645EXPORT_SYMBOL(__devm_release_region);
1646
1647/*
1648 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1649 */
1650#define MAXRESERVE 4
1651static int __init reserve_setup(char *str)
1652{
1653 static int reserved;
1654 static struct resource reserve[MAXRESERVE];
1655
1656 for (;;) {
1657 unsigned int io_start, io_num;
1658 int x = reserved;
1659 struct resource *parent;
1660
1661 if (get_option(&str, &io_start) != 2)
1662 break;
1663 if (get_option(&str, &io_num) == 0)
1664 break;
1665 if (x < MAXRESERVE) {
1666 struct resource *res = reserve + x;
1667
1668 /*
1669 * If the region starts below 0x10000, we assume it's
1670 * I/O port space; otherwise assume it's memory.
1671 */
1672 if (io_start < 0x10000) {
1673 res->flags = IORESOURCE_IO;
1674 parent = &ioport_resource;
1675 } else {
1676 res->flags = IORESOURCE_MEM;
1677 parent = &iomem_resource;
1678 }
1679 res->name = "reserved";
1680 res->start = io_start;
1681 res->end = io_start + io_num - 1;
1682 res->flags |= IORESOURCE_BUSY;
1683 res->desc = IORES_DESC_NONE;
1684 res->child = NULL;
1685 if (request_resource(parent, res) == 0)
1686 reserved = x+1;
1687 }
1688 }
1689 return 1;
1690}
1691__setup("reserve=", reserve_setup);
1692
1693/*
1694 * Check if the requested addr and size spans more than any slot in the
1695 * iomem resource tree.
1696 */
1697int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1698{
1699 resource_size_t end = addr + size - 1;
1700 struct resource *p;
1701 int err = 0;
1702
1703 read_lock(&resource_lock);
1704 for_each_resource(&iomem_resource, p, false) {
1705 /*
1706 * We can probably skip the resources without
1707 * IORESOURCE_IO attribute?
1708 */
1709 if (p->start > end)
1710 continue;
1711 if (p->end < addr)
1712 continue;
1713 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1714 PFN_DOWN(p->end) >= PFN_DOWN(end))
1715 continue;
1716 /*
1717 * if a resource is "BUSY", it's not a hardware resource
1718 * but a driver mapping of such a resource; we don't want
1719 * to warn for those; some drivers legitimately map only
1720 * partial hardware resources. (example: vesafb)
1721 */
1722 if (p->flags & IORESOURCE_BUSY)
1723 continue;
1724
1725 pr_warn("resource sanity check: requesting [mem %pa-%pa], which spans more than %s %pR\n",
1726 &addr, &end, p->name, p);
1727 err = -1;
1728 break;
1729 }
1730 read_unlock(&resource_lock);
1731
1732 return err;
1733}
1734
1735#ifdef CONFIG_STRICT_DEVMEM
1736static int strict_iomem_checks = 1;
1737#else
1738static int strict_iomem_checks;
1739#endif
1740
1741/*
1742 * Check if an address is exclusive to the kernel and must not be mapped to
1743 * user space, for example, via /dev/mem.
1744 *
1745 * Returns true if exclusive to the kernel, otherwise returns false.
1746 */
1747bool resource_is_exclusive(struct resource *root, u64 addr, resource_size_t size)
1748{
1749 const unsigned int exclusive_system_ram = IORESOURCE_SYSTEM_RAM |
1750 IORESOURCE_EXCLUSIVE;
1751 bool skip_children = false, err = false;
1752 struct resource *p;
1753
1754 read_lock(&resource_lock);
1755 for_each_resource(root, p, skip_children) {
1756 if (p->start >= addr + size)
1757 break;
1758 if (p->end < addr) {
1759 skip_children = true;
1760 continue;
1761 }
1762 skip_children = false;
1763
1764 /*
1765 * IORESOURCE_SYSTEM_RAM resources are exclusive if
1766 * IORESOURCE_EXCLUSIVE is set, even if they
1767 * are not busy and even if "iomem=relaxed" is set. The
1768 * responsible driver dynamically adds/removes system RAM within
1769 * such an area and uncontrolled access is dangerous.
1770 */
1771 if ((p->flags & exclusive_system_ram) == exclusive_system_ram) {
1772 err = true;
1773 break;
1774 }
1775
1776 /*
1777 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1778 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1779 * resource is busy.
1780 */
1781 if (!strict_iomem_checks || !(p->flags & IORESOURCE_BUSY))
1782 continue;
1783 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1784 || p->flags & IORESOURCE_EXCLUSIVE) {
1785 err = true;
1786 break;
1787 }
1788 }
1789 read_unlock(&resource_lock);
1790
1791 return err;
1792}
1793
1794bool iomem_is_exclusive(u64 addr)
1795{
1796 return resource_is_exclusive(&iomem_resource, addr & PAGE_MASK,
1797 PAGE_SIZE);
1798}
1799
1800struct resource_entry *resource_list_create_entry(struct resource *res,
1801 size_t extra_size)
1802{
1803 struct resource_entry *entry;
1804
1805 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1806 if (entry) {
1807 INIT_LIST_HEAD(&entry->node);
1808 entry->res = res ? res : &entry->__res;
1809 }
1810
1811 return entry;
1812}
1813EXPORT_SYMBOL(resource_list_create_entry);
1814
1815void resource_list_free(struct list_head *head)
1816{
1817 struct resource_entry *entry, *tmp;
1818
1819 list_for_each_entry_safe(entry, tmp, head, node)
1820 resource_list_destroy_entry(entry);
1821}
1822EXPORT_SYMBOL(resource_list_free);
1823
1824#ifdef CONFIG_GET_FREE_REGION
1825#define GFR_DESCENDING (1UL << 0)
1826#define GFR_REQUEST_REGION (1UL << 1)
1827#define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT)
1828
1829static resource_size_t gfr_start(struct resource *base, resource_size_t size,
1830 resource_size_t align, unsigned long flags)
1831{
1832 if (flags & GFR_DESCENDING) {
1833 resource_size_t end;
1834
1835 end = min_t(resource_size_t, base->end,
1836 (1ULL << MAX_PHYSMEM_BITS) - 1);
1837 return end - size + 1;
1838 }
1839
1840 return ALIGN(base->start, align);
1841}
1842
1843static bool gfr_continue(struct resource *base, resource_size_t addr,
1844 resource_size_t size, unsigned long flags)
1845{
1846 if (flags & GFR_DESCENDING)
1847 return addr > size && addr >= base->start;
1848 /*
1849 * In the ascend case be careful that the last increment by
1850 * @size did not wrap 0.
1851 */
1852 return addr > addr - size &&
1853 addr <= min_t(resource_size_t, base->end,
1854 (1ULL << MAX_PHYSMEM_BITS) - 1);
1855}
1856
1857static resource_size_t gfr_next(resource_size_t addr, resource_size_t size,
1858 unsigned long flags)
1859{
1860 if (flags & GFR_DESCENDING)
1861 return addr - size;
1862 return addr + size;
1863}
1864
1865static void remove_free_mem_region(void *_res)
1866{
1867 struct resource *res = _res;
1868
1869 if (res->parent)
1870 remove_resource(res);
1871 free_resource(res);
1872}
1873
1874static struct resource *
1875get_free_mem_region(struct device *dev, struct resource *base,
1876 resource_size_t size, const unsigned long align,
1877 const char *name, const unsigned long desc,
1878 const unsigned long flags)
1879{
1880 resource_size_t addr;
1881 struct resource *res;
1882 struct region_devres *dr = NULL;
1883
1884 size = ALIGN(size, align);
1885
1886 res = alloc_resource(GFP_KERNEL);
1887 if (!res)
1888 return ERR_PTR(-ENOMEM);
1889
1890 if (dev && (flags & GFR_REQUEST_REGION)) {
1891 dr = devres_alloc(devm_region_release,
1892 sizeof(struct region_devres), GFP_KERNEL);
1893 if (!dr) {
1894 free_resource(res);
1895 return ERR_PTR(-ENOMEM);
1896 }
1897 } else if (dev) {
1898 if (devm_add_action_or_reset(dev, remove_free_mem_region, res))
1899 return ERR_PTR(-ENOMEM);
1900 }
1901
1902 write_lock(&resource_lock);
1903 for (addr = gfr_start(base, size, align, flags);
1904 gfr_continue(base, addr, align, flags);
1905 addr = gfr_next(addr, align, flags)) {
1906 if (__region_intersects(base, addr, size, 0, IORES_DESC_NONE) !=
1907 REGION_DISJOINT)
1908 continue;
1909
1910 if (flags & GFR_REQUEST_REGION) {
1911 if (__request_region_locked(res, &iomem_resource, addr,
1912 size, name, 0))
1913 break;
1914
1915 if (dev) {
1916 dr->parent = &iomem_resource;
1917 dr->start = addr;
1918 dr->n = size;
1919 devres_add(dev, dr);
1920 }
1921
1922 res->desc = desc;
1923 write_unlock(&resource_lock);
1924
1925
1926 /*
1927 * A driver is claiming this region so revoke any
1928 * mappings.
1929 */
1930 revoke_iomem(res);
1931 } else {
1932 res->start = addr;
1933 res->end = addr + size - 1;
1934 res->name = name;
1935 res->desc = desc;
1936 res->flags = IORESOURCE_MEM;
1937
1938 /*
1939 * Only succeed if the resource hosts an exclusive
1940 * range after the insert
1941 */
1942 if (__insert_resource(base, res) || res->child)
1943 break;
1944
1945 write_unlock(&resource_lock);
1946 }
1947
1948 return res;
1949 }
1950 write_unlock(&resource_lock);
1951
1952 if (flags & GFR_REQUEST_REGION) {
1953 free_resource(res);
1954 devres_free(dr);
1955 } else if (dev)
1956 devm_release_action(dev, remove_free_mem_region, res);
1957
1958 return ERR_PTR(-ERANGE);
1959}
1960
1961/**
1962 * devm_request_free_mem_region - find free region for device private memory
1963 *
1964 * @dev: device struct to bind the resource to
1965 * @size: size in bytes of the device memory to add
1966 * @base: resource tree to look in
1967 *
1968 * This function tries to find an empty range of physical address big enough to
1969 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1970 * memory, which in turn allocates struct pages.
1971 */
1972struct resource *devm_request_free_mem_region(struct device *dev,
1973 struct resource *base, unsigned long size)
1974{
1975 unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
1976
1977 return get_free_mem_region(dev, base, size, GFR_DEFAULT_ALIGN,
1978 dev_name(dev),
1979 IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
1980}
1981EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
1982
1983struct resource *request_free_mem_region(struct resource *base,
1984 unsigned long size, const char *name)
1985{
1986 unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
1987
1988 return get_free_mem_region(NULL, base, size, GFR_DEFAULT_ALIGN, name,
1989 IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
1990}
1991EXPORT_SYMBOL_GPL(request_free_mem_region);
1992
1993/**
1994 * alloc_free_mem_region - find a free region relative to @base
1995 * @base: resource that will parent the new resource
1996 * @size: size in bytes of memory to allocate from @base
1997 * @align: alignment requirements for the allocation
1998 * @name: resource name
1999 *
2000 * Buses like CXL, that can dynamically instantiate new memory regions,
2001 * need a method to allocate physical address space for those regions.
2002 * Allocate and insert a new resource to cover a free, unclaimed by a
2003 * descendant of @base, range in the span of @base.
2004 */
2005struct resource *alloc_free_mem_region(struct resource *base,
2006 unsigned long size, unsigned long align,
2007 const char *name)
2008{
2009 /* Default of ascending direction and insert resource */
2010 unsigned long flags = 0;
2011
2012 return get_free_mem_region(NULL, base, size, align, name,
2013 IORES_DESC_NONE, flags);
2014}
2015EXPORT_SYMBOL_NS_GPL(alloc_free_mem_region, CXL);
2016#endif /* CONFIG_GET_FREE_REGION */
2017
2018static int __init strict_iomem(char *str)
2019{
2020 if (strstr(str, "relaxed"))
2021 strict_iomem_checks = 0;
2022 if (strstr(str, "strict"))
2023 strict_iomem_checks = 1;
2024 return 1;
2025}
2026
2027static int iomem_fs_init_fs_context(struct fs_context *fc)
2028{
2029 return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM;
2030}
2031
2032static struct file_system_type iomem_fs_type = {
2033 .name = "iomem",
2034 .owner = THIS_MODULE,
2035 .init_fs_context = iomem_fs_init_fs_context,
2036 .kill_sb = kill_anon_super,
2037};
2038
2039static int __init iomem_init_inode(void)
2040{
2041 static struct vfsmount *iomem_vfs_mount;
2042 static int iomem_fs_cnt;
2043 struct inode *inode;
2044 int rc;
2045
2046 rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt);
2047 if (rc < 0) {
2048 pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc);
2049 return rc;
2050 }
2051
2052 inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb);
2053 if (IS_ERR(inode)) {
2054 rc = PTR_ERR(inode);
2055 pr_err("Cannot allocate inode for iomem: %d\n", rc);
2056 simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt);
2057 return rc;
2058 }
2059
2060 /*
2061 * Publish iomem revocation inode initialized.
2062 * Pairs with smp_load_acquire() in revoke_iomem().
2063 */
2064 smp_store_release(&iomem_inode, inode);
2065
2066 return 0;
2067}
2068
2069fs_initcall(iomem_init_inode);
2070
2071__setup("iomem=", strict_iomem);