Loading...
1/*
2 * linux/kernel/resource.c
3 *
4 * Copyright (C) 1999 Linus Torvalds
5 * Copyright (C) 1999 Martin Mares <mj@ucw.cz>
6 *
7 * Arbitrary resource management.
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/export.h>
13#include <linux/errno.h>
14#include <linux/ioport.h>
15#include <linux/init.h>
16#include <linux/slab.h>
17#include <linux/spinlock.h>
18#include <linux/fs.h>
19#include <linux/proc_fs.h>
20#include <linux/sched.h>
21#include <linux/seq_file.h>
22#include <linux/device.h>
23#include <linux/pfn.h>
24#include <linux/mm.h>
25#include <linux/resource_ext.h>
26#include <asm/io.h>
27
28
29struct resource ioport_resource = {
30 .name = "PCI IO",
31 .start = 0,
32 .end = IO_SPACE_LIMIT,
33 .flags = IORESOURCE_IO,
34};
35EXPORT_SYMBOL(ioport_resource);
36
37struct resource iomem_resource = {
38 .name = "PCI mem",
39 .start = 0,
40 .end = -1,
41 .flags = IORESOURCE_MEM,
42};
43EXPORT_SYMBOL(iomem_resource);
44
45/* constraints to be met while allocating resources */
46struct resource_constraint {
47 resource_size_t min, max, align;
48 resource_size_t (*alignf)(void *, const struct resource *,
49 resource_size_t, resource_size_t);
50 void *alignf_data;
51};
52
53static DEFINE_RWLOCK(resource_lock);
54
55/*
56 * For memory hotplug, there is no way to free resource entries allocated
57 * by boot mem after the system is up. So for reusing the resource entry
58 * we need to remember the resource.
59 */
60static struct resource *bootmem_resource_free;
61static DEFINE_SPINLOCK(bootmem_resource_lock);
62
63static struct resource *next_resource(struct resource *p, bool sibling_only)
64{
65 /* Caller wants to traverse through siblings only */
66 if (sibling_only)
67 return p->sibling;
68
69 if (p->child)
70 return p->child;
71 while (!p->sibling && p->parent)
72 p = p->parent;
73 return p->sibling;
74}
75
76static void *r_next(struct seq_file *m, void *v, loff_t *pos)
77{
78 struct resource *p = v;
79 (*pos)++;
80 return (void *)next_resource(p, false);
81}
82
83#ifdef CONFIG_PROC_FS
84
85enum { MAX_IORES_LEVEL = 5 };
86
87static void *r_start(struct seq_file *m, loff_t *pos)
88 __acquires(resource_lock)
89{
90 struct resource *p = m->private;
91 loff_t l = 0;
92 read_lock(&resource_lock);
93 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
94 ;
95 return p;
96}
97
98static void r_stop(struct seq_file *m, void *v)
99 __releases(resource_lock)
100{
101 read_unlock(&resource_lock);
102}
103
104static int r_show(struct seq_file *m, void *v)
105{
106 struct resource *root = m->private;
107 struct resource *r = v, *p;
108 unsigned long long start, end;
109 int width = root->end < 0x10000 ? 4 : 8;
110 int depth;
111
112 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
113 if (p->parent == root)
114 break;
115
116 if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
117 start = r->start;
118 end = r->end;
119 } else {
120 start = end = 0;
121 }
122
123 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
124 depth * 2, "",
125 width, start,
126 width, end,
127 r->name ? r->name : "<BAD>");
128 return 0;
129}
130
131static const struct seq_operations resource_op = {
132 .start = r_start,
133 .next = r_next,
134 .stop = r_stop,
135 .show = r_show,
136};
137
138static int ioports_open(struct inode *inode, struct file *file)
139{
140 int res = seq_open(file, &resource_op);
141 if (!res) {
142 struct seq_file *m = file->private_data;
143 m->private = &ioport_resource;
144 }
145 return res;
146}
147
148static int iomem_open(struct inode *inode, struct file *file)
149{
150 int res = seq_open(file, &resource_op);
151 if (!res) {
152 struct seq_file *m = file->private_data;
153 m->private = &iomem_resource;
154 }
155 return res;
156}
157
158static const struct file_operations proc_ioports_operations = {
159 .open = ioports_open,
160 .read = seq_read,
161 .llseek = seq_lseek,
162 .release = seq_release,
163};
164
165static const struct file_operations proc_iomem_operations = {
166 .open = iomem_open,
167 .read = seq_read,
168 .llseek = seq_lseek,
169 .release = seq_release,
170};
171
172static int __init ioresources_init(void)
173{
174 proc_create("ioports", 0, NULL, &proc_ioports_operations);
175 proc_create("iomem", 0, NULL, &proc_iomem_operations);
176 return 0;
177}
178__initcall(ioresources_init);
179
180#endif /* CONFIG_PROC_FS */
181
182static void free_resource(struct resource *res)
183{
184 if (!res)
185 return;
186
187 if (!PageSlab(virt_to_head_page(res))) {
188 spin_lock(&bootmem_resource_lock);
189 res->sibling = bootmem_resource_free;
190 bootmem_resource_free = res;
191 spin_unlock(&bootmem_resource_lock);
192 } else {
193 kfree(res);
194 }
195}
196
197static struct resource *alloc_resource(gfp_t flags)
198{
199 struct resource *res = NULL;
200
201 spin_lock(&bootmem_resource_lock);
202 if (bootmem_resource_free) {
203 res = bootmem_resource_free;
204 bootmem_resource_free = res->sibling;
205 }
206 spin_unlock(&bootmem_resource_lock);
207
208 if (res)
209 memset(res, 0, sizeof(struct resource));
210 else
211 res = kzalloc(sizeof(struct resource), flags);
212
213 return res;
214}
215
216/* Return the conflict entry if you can't request it */
217static struct resource * __request_resource(struct resource *root, struct resource *new)
218{
219 resource_size_t start = new->start;
220 resource_size_t end = new->end;
221 struct resource *tmp, **p;
222
223 if (end < start)
224 return root;
225 if (start < root->start)
226 return root;
227 if (end > root->end)
228 return root;
229 p = &root->child;
230 for (;;) {
231 tmp = *p;
232 if (!tmp || tmp->start > end) {
233 new->sibling = tmp;
234 *p = new;
235 new->parent = root;
236 return NULL;
237 }
238 p = &tmp->sibling;
239 if (tmp->end < start)
240 continue;
241 return tmp;
242 }
243}
244
245static int __release_resource(struct resource *old, bool release_child)
246{
247 struct resource *tmp, **p, *chd;
248
249 p = &old->parent->child;
250 for (;;) {
251 tmp = *p;
252 if (!tmp)
253 break;
254 if (tmp == old) {
255 if (release_child || !(tmp->child)) {
256 *p = tmp->sibling;
257 } else {
258 for (chd = tmp->child;; chd = chd->sibling) {
259 chd->parent = tmp->parent;
260 if (!(chd->sibling))
261 break;
262 }
263 *p = tmp->child;
264 chd->sibling = tmp->sibling;
265 }
266 old->parent = NULL;
267 return 0;
268 }
269 p = &tmp->sibling;
270 }
271 return -EINVAL;
272}
273
274static void __release_child_resources(struct resource *r)
275{
276 struct resource *tmp, *p;
277 resource_size_t size;
278
279 p = r->child;
280 r->child = NULL;
281 while (p) {
282 tmp = p;
283 p = p->sibling;
284
285 tmp->parent = NULL;
286 tmp->sibling = NULL;
287 __release_child_resources(tmp);
288
289 printk(KERN_DEBUG "release child resource %pR\n", tmp);
290 /* need to restore size, and keep flags */
291 size = resource_size(tmp);
292 tmp->start = 0;
293 tmp->end = size - 1;
294 }
295}
296
297void release_child_resources(struct resource *r)
298{
299 write_lock(&resource_lock);
300 __release_child_resources(r);
301 write_unlock(&resource_lock);
302}
303
304/**
305 * request_resource_conflict - request and reserve an I/O or memory resource
306 * @root: root resource descriptor
307 * @new: resource descriptor desired by caller
308 *
309 * Returns 0 for success, conflict resource on error.
310 */
311struct resource *request_resource_conflict(struct resource *root, struct resource *new)
312{
313 struct resource *conflict;
314
315 write_lock(&resource_lock);
316 conflict = __request_resource(root, new);
317 write_unlock(&resource_lock);
318 return conflict;
319}
320
321/**
322 * request_resource - request and reserve an I/O or memory resource
323 * @root: root resource descriptor
324 * @new: resource descriptor desired by caller
325 *
326 * Returns 0 for success, negative error code on error.
327 */
328int request_resource(struct resource *root, struct resource *new)
329{
330 struct resource *conflict;
331
332 conflict = request_resource_conflict(root, new);
333 return conflict ? -EBUSY : 0;
334}
335
336EXPORT_SYMBOL(request_resource);
337
338/**
339 * release_resource - release a previously reserved resource
340 * @old: resource pointer
341 */
342int release_resource(struct resource *old)
343{
344 int retval;
345
346 write_lock(&resource_lock);
347 retval = __release_resource(old, true);
348 write_unlock(&resource_lock);
349 return retval;
350}
351
352EXPORT_SYMBOL(release_resource);
353
354/*
355 * Finds the lowest iomem resource existing within [res->start.res->end).
356 * The caller must specify res->start, res->end, res->flags, and optionally
357 * desc. If found, returns 0, res is overwritten, if not found, returns -1.
358 * This function walks the whole tree and not just first level children until
359 * and unless first_level_children_only is true.
360 */
361static int find_next_iomem_res(struct resource *res, unsigned long desc,
362 bool first_level_children_only)
363{
364 resource_size_t start, end;
365 struct resource *p;
366 bool sibling_only = false;
367
368 BUG_ON(!res);
369
370 start = res->start;
371 end = res->end;
372 BUG_ON(start >= end);
373
374 if (first_level_children_only)
375 sibling_only = true;
376
377 read_lock(&resource_lock);
378
379 for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
380 if ((p->flags & res->flags) != res->flags)
381 continue;
382 if ((desc != IORES_DESC_NONE) && (desc != p->desc))
383 continue;
384 if (p->start > end) {
385 p = NULL;
386 break;
387 }
388 if ((p->end >= start) && (p->start < end))
389 break;
390 }
391
392 read_unlock(&resource_lock);
393 if (!p)
394 return -1;
395 /* copy data */
396 if (res->start < p->start)
397 res->start = p->start;
398 if (res->end > p->end)
399 res->end = p->end;
400 return 0;
401}
402
403/*
404 * Walks through iomem resources and calls func() with matching resource
405 * ranges. This walks through whole tree and not just first level children.
406 * All the memory ranges which overlap start,end and also match flags and
407 * desc are valid candidates.
408 *
409 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
410 * @flags: I/O resource flags
411 * @start: start addr
412 * @end: end addr
413 *
414 * NOTE: For a new descriptor search, define a new IORES_DESC in
415 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
416 */
417int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
418 u64 end, void *arg, int (*func)(u64, u64, void *))
419{
420 struct resource res;
421 u64 orig_end;
422 int ret = -1;
423
424 res.start = start;
425 res.end = end;
426 res.flags = flags;
427 orig_end = res.end;
428
429 while ((res.start < res.end) &&
430 (!find_next_iomem_res(&res, desc, false))) {
431
432 ret = (*func)(res.start, res.end, arg);
433 if (ret)
434 break;
435
436 res.start = res.end + 1;
437 res.end = orig_end;
438 }
439
440 return ret;
441}
442
443/*
444 * This function calls the @func callback against all memory ranges of type
445 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
446 * Now, this function is only for System RAM, it deals with full ranges and
447 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
448 * ranges.
449 */
450int walk_system_ram_res(u64 start, u64 end, void *arg,
451 int (*func)(u64, u64, void *))
452{
453 struct resource res;
454 u64 orig_end;
455 int ret = -1;
456
457 res.start = start;
458 res.end = end;
459 res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
460 orig_end = res.end;
461 while ((res.start < res.end) &&
462 (!find_next_iomem_res(&res, IORES_DESC_NONE, true))) {
463 ret = (*func)(res.start, res.end, arg);
464 if (ret)
465 break;
466 res.start = res.end + 1;
467 res.end = orig_end;
468 }
469 return ret;
470}
471
472#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
473
474/*
475 * This function calls the @func callback against all memory ranges of type
476 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
477 * It is to be used only for System RAM.
478 */
479int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
480 void *arg, int (*func)(unsigned long, unsigned long, void *))
481{
482 struct resource res;
483 unsigned long pfn, end_pfn;
484 u64 orig_end;
485 int ret = -1;
486
487 res.start = (u64) start_pfn << PAGE_SHIFT;
488 res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
489 res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
490 orig_end = res.end;
491 while ((res.start < res.end) &&
492 (find_next_iomem_res(&res, IORES_DESC_NONE, true) >= 0)) {
493 pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
494 end_pfn = (res.end + 1) >> PAGE_SHIFT;
495 if (end_pfn > pfn)
496 ret = (*func)(pfn, end_pfn - pfn, arg);
497 if (ret)
498 break;
499 res.start = res.end + 1;
500 res.end = orig_end;
501 }
502 return ret;
503}
504
505#endif
506
507static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
508{
509 return 1;
510}
511/*
512 * This generic page_is_ram() returns true if specified address is
513 * registered as System RAM in iomem_resource list.
514 */
515int __weak page_is_ram(unsigned long pfn)
516{
517 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
518}
519EXPORT_SYMBOL_GPL(page_is_ram);
520
521/**
522 * region_intersects() - determine intersection of region with known resources
523 * @start: region start address
524 * @size: size of region
525 * @flags: flags of resource (in iomem_resource)
526 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
527 *
528 * Check if the specified region partially overlaps or fully eclipses a
529 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
530 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
531 * return REGION_MIXED if the region overlaps @flags/@desc and another
532 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
533 * and no other defined resource. Note that REGION_INTERSECTS is also
534 * returned in the case when the specified region overlaps RAM and undefined
535 * memory holes.
536 *
537 * region_intersect() is used by memory remapping functions to ensure
538 * the user is not remapping RAM and is a vast speed up over walking
539 * through the resource table page by page.
540 */
541int region_intersects(resource_size_t start, size_t size, unsigned long flags,
542 unsigned long desc)
543{
544 resource_size_t end = start + size - 1;
545 int type = 0; int other = 0;
546 struct resource *p;
547
548 read_lock(&resource_lock);
549 for (p = iomem_resource.child; p ; p = p->sibling) {
550 bool is_type = (((p->flags & flags) == flags) &&
551 ((desc == IORES_DESC_NONE) ||
552 (desc == p->desc)));
553
554 if (start >= p->start && start <= p->end)
555 is_type ? type++ : other++;
556 if (end >= p->start && end <= p->end)
557 is_type ? type++ : other++;
558 if (p->start >= start && p->end <= end)
559 is_type ? type++ : other++;
560 }
561 read_unlock(&resource_lock);
562
563 if (other == 0)
564 return type ? REGION_INTERSECTS : REGION_DISJOINT;
565
566 if (type)
567 return REGION_MIXED;
568
569 return REGION_DISJOINT;
570}
571EXPORT_SYMBOL_GPL(region_intersects);
572
573void __weak arch_remove_reservations(struct resource *avail)
574{
575}
576
577static resource_size_t simple_align_resource(void *data,
578 const struct resource *avail,
579 resource_size_t size,
580 resource_size_t align)
581{
582 return avail->start;
583}
584
585static void resource_clip(struct resource *res, resource_size_t min,
586 resource_size_t max)
587{
588 if (res->start < min)
589 res->start = min;
590 if (res->end > max)
591 res->end = max;
592}
593
594/*
595 * Find empty slot in the resource tree with the given range and
596 * alignment constraints
597 */
598static int __find_resource(struct resource *root, struct resource *old,
599 struct resource *new,
600 resource_size_t size,
601 struct resource_constraint *constraint)
602{
603 struct resource *this = root->child;
604 struct resource tmp = *new, avail, alloc;
605
606 tmp.start = root->start;
607 /*
608 * Skip past an allocated resource that starts at 0, since the assignment
609 * of this->start - 1 to tmp->end below would cause an underflow.
610 */
611 if (this && this->start == root->start) {
612 tmp.start = (this == old) ? old->start : this->end + 1;
613 this = this->sibling;
614 }
615 for(;;) {
616 if (this)
617 tmp.end = (this == old) ? this->end : this->start - 1;
618 else
619 tmp.end = root->end;
620
621 if (tmp.end < tmp.start)
622 goto next;
623
624 resource_clip(&tmp, constraint->min, constraint->max);
625 arch_remove_reservations(&tmp);
626
627 /* Check for overflow after ALIGN() */
628 avail.start = ALIGN(tmp.start, constraint->align);
629 avail.end = tmp.end;
630 avail.flags = new->flags & ~IORESOURCE_UNSET;
631 if (avail.start >= tmp.start) {
632 alloc.flags = avail.flags;
633 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
634 size, constraint->align);
635 alloc.end = alloc.start + size - 1;
636 if (resource_contains(&avail, &alloc)) {
637 new->start = alloc.start;
638 new->end = alloc.end;
639 return 0;
640 }
641 }
642
643next: if (!this || this->end == root->end)
644 break;
645
646 if (this != old)
647 tmp.start = this->end + 1;
648 this = this->sibling;
649 }
650 return -EBUSY;
651}
652
653/*
654 * Find empty slot in the resource tree given range and alignment.
655 */
656static int find_resource(struct resource *root, struct resource *new,
657 resource_size_t size,
658 struct resource_constraint *constraint)
659{
660 return __find_resource(root, NULL, new, size, constraint);
661}
662
663/**
664 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
665 * The resource will be relocated if the new size cannot be reallocated in the
666 * current location.
667 *
668 * @root: root resource descriptor
669 * @old: resource descriptor desired by caller
670 * @newsize: new size of the resource descriptor
671 * @constraint: the size and alignment constraints to be met.
672 */
673static int reallocate_resource(struct resource *root, struct resource *old,
674 resource_size_t newsize,
675 struct resource_constraint *constraint)
676{
677 int err=0;
678 struct resource new = *old;
679 struct resource *conflict;
680
681 write_lock(&resource_lock);
682
683 if ((err = __find_resource(root, old, &new, newsize, constraint)))
684 goto out;
685
686 if (resource_contains(&new, old)) {
687 old->start = new.start;
688 old->end = new.end;
689 goto out;
690 }
691
692 if (old->child) {
693 err = -EBUSY;
694 goto out;
695 }
696
697 if (resource_contains(old, &new)) {
698 old->start = new.start;
699 old->end = new.end;
700 } else {
701 __release_resource(old, true);
702 *old = new;
703 conflict = __request_resource(root, old);
704 BUG_ON(conflict);
705 }
706out:
707 write_unlock(&resource_lock);
708 return err;
709}
710
711
712/**
713 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
714 * The resource will be reallocated with a new size if it was already allocated
715 * @root: root resource descriptor
716 * @new: resource descriptor desired by caller
717 * @size: requested resource region size
718 * @min: minimum boundary to allocate
719 * @max: maximum boundary to allocate
720 * @align: alignment requested, in bytes
721 * @alignf: alignment function, optional, called if not NULL
722 * @alignf_data: arbitrary data to pass to the @alignf function
723 */
724int allocate_resource(struct resource *root, struct resource *new,
725 resource_size_t size, resource_size_t min,
726 resource_size_t max, resource_size_t align,
727 resource_size_t (*alignf)(void *,
728 const struct resource *,
729 resource_size_t,
730 resource_size_t),
731 void *alignf_data)
732{
733 int err;
734 struct resource_constraint constraint;
735
736 if (!alignf)
737 alignf = simple_align_resource;
738
739 constraint.min = min;
740 constraint.max = max;
741 constraint.align = align;
742 constraint.alignf = alignf;
743 constraint.alignf_data = alignf_data;
744
745 if ( new->parent ) {
746 /* resource is already allocated, try reallocating with
747 the new constraints */
748 return reallocate_resource(root, new, size, &constraint);
749 }
750
751 write_lock(&resource_lock);
752 err = find_resource(root, new, size, &constraint);
753 if (err >= 0 && __request_resource(root, new))
754 err = -EBUSY;
755 write_unlock(&resource_lock);
756 return err;
757}
758
759EXPORT_SYMBOL(allocate_resource);
760
761/**
762 * lookup_resource - find an existing resource by a resource start address
763 * @root: root resource descriptor
764 * @start: resource start address
765 *
766 * Returns a pointer to the resource if found, NULL otherwise
767 */
768struct resource *lookup_resource(struct resource *root, resource_size_t start)
769{
770 struct resource *res;
771
772 read_lock(&resource_lock);
773 for (res = root->child; res; res = res->sibling) {
774 if (res->start == start)
775 break;
776 }
777 read_unlock(&resource_lock);
778
779 return res;
780}
781
782/*
783 * Insert a resource into the resource tree. If successful, return NULL,
784 * otherwise return the conflicting resource (compare to __request_resource())
785 */
786static struct resource * __insert_resource(struct resource *parent, struct resource *new)
787{
788 struct resource *first, *next;
789
790 for (;; parent = first) {
791 first = __request_resource(parent, new);
792 if (!first)
793 return first;
794
795 if (first == parent)
796 return first;
797 if (WARN_ON(first == new)) /* duplicated insertion */
798 return first;
799
800 if ((first->start > new->start) || (first->end < new->end))
801 break;
802 if ((first->start == new->start) && (first->end == new->end))
803 break;
804 }
805
806 for (next = first; ; next = next->sibling) {
807 /* Partial overlap? Bad, and unfixable */
808 if (next->start < new->start || next->end > new->end)
809 return next;
810 if (!next->sibling)
811 break;
812 if (next->sibling->start > new->end)
813 break;
814 }
815
816 new->parent = parent;
817 new->sibling = next->sibling;
818 new->child = first;
819
820 next->sibling = NULL;
821 for (next = first; next; next = next->sibling)
822 next->parent = new;
823
824 if (parent->child == first) {
825 parent->child = new;
826 } else {
827 next = parent->child;
828 while (next->sibling != first)
829 next = next->sibling;
830 next->sibling = new;
831 }
832 return NULL;
833}
834
835/**
836 * insert_resource_conflict - Inserts resource in the resource tree
837 * @parent: parent of the new resource
838 * @new: new resource to insert
839 *
840 * Returns 0 on success, conflict resource if the resource can't be inserted.
841 *
842 * This function is equivalent to request_resource_conflict when no conflict
843 * happens. If a conflict happens, and the conflicting resources
844 * entirely fit within the range of the new resource, then the new
845 * resource is inserted and the conflicting resources become children of
846 * the new resource.
847 *
848 * This function is intended for producers of resources, such as FW modules
849 * and bus drivers.
850 */
851struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
852{
853 struct resource *conflict;
854
855 write_lock(&resource_lock);
856 conflict = __insert_resource(parent, new);
857 write_unlock(&resource_lock);
858 return conflict;
859}
860
861/**
862 * insert_resource - Inserts a resource in the resource tree
863 * @parent: parent of the new resource
864 * @new: new resource to insert
865 *
866 * Returns 0 on success, -EBUSY if the resource can't be inserted.
867 *
868 * This function is intended for producers of resources, such as FW modules
869 * and bus drivers.
870 */
871int insert_resource(struct resource *parent, struct resource *new)
872{
873 struct resource *conflict;
874
875 conflict = insert_resource_conflict(parent, new);
876 return conflict ? -EBUSY : 0;
877}
878EXPORT_SYMBOL_GPL(insert_resource);
879
880/**
881 * insert_resource_expand_to_fit - Insert a resource into the resource tree
882 * @root: root resource descriptor
883 * @new: new resource to insert
884 *
885 * Insert a resource into the resource tree, possibly expanding it in order
886 * to make it encompass any conflicting resources.
887 */
888void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
889{
890 if (new->parent)
891 return;
892
893 write_lock(&resource_lock);
894 for (;;) {
895 struct resource *conflict;
896
897 conflict = __insert_resource(root, new);
898 if (!conflict)
899 break;
900 if (conflict == root)
901 break;
902
903 /* Ok, expand resource to cover the conflict, then try again .. */
904 if (conflict->start < new->start)
905 new->start = conflict->start;
906 if (conflict->end > new->end)
907 new->end = conflict->end;
908
909 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
910 }
911 write_unlock(&resource_lock);
912}
913
914/**
915 * remove_resource - Remove a resource in the resource tree
916 * @old: resource to remove
917 *
918 * Returns 0 on success, -EINVAL if the resource is not valid.
919 *
920 * This function removes a resource previously inserted by insert_resource()
921 * or insert_resource_conflict(), and moves the children (if any) up to
922 * where they were before. insert_resource() and insert_resource_conflict()
923 * insert a new resource, and move any conflicting resources down to the
924 * children of the new resource.
925 *
926 * insert_resource(), insert_resource_conflict() and remove_resource() are
927 * intended for producers of resources, such as FW modules and bus drivers.
928 */
929int remove_resource(struct resource *old)
930{
931 int retval;
932
933 write_lock(&resource_lock);
934 retval = __release_resource(old, false);
935 write_unlock(&resource_lock);
936 return retval;
937}
938EXPORT_SYMBOL_GPL(remove_resource);
939
940static int __adjust_resource(struct resource *res, resource_size_t start,
941 resource_size_t size)
942{
943 struct resource *tmp, *parent = res->parent;
944 resource_size_t end = start + size - 1;
945 int result = -EBUSY;
946
947 if (!parent)
948 goto skip;
949
950 if ((start < parent->start) || (end > parent->end))
951 goto out;
952
953 if (res->sibling && (res->sibling->start <= end))
954 goto out;
955
956 tmp = parent->child;
957 if (tmp != res) {
958 while (tmp->sibling != res)
959 tmp = tmp->sibling;
960 if (start <= tmp->end)
961 goto out;
962 }
963
964skip:
965 for (tmp = res->child; tmp; tmp = tmp->sibling)
966 if ((tmp->start < start) || (tmp->end > end))
967 goto out;
968
969 res->start = start;
970 res->end = end;
971 result = 0;
972
973 out:
974 return result;
975}
976
977/**
978 * adjust_resource - modify a resource's start and size
979 * @res: resource to modify
980 * @start: new start value
981 * @size: new size
982 *
983 * Given an existing resource, change its start and size to match the
984 * arguments. Returns 0 on success, -EBUSY if it can't fit.
985 * Existing children of the resource are assumed to be immutable.
986 */
987int adjust_resource(struct resource *res, resource_size_t start,
988 resource_size_t size)
989{
990 int result;
991
992 write_lock(&resource_lock);
993 result = __adjust_resource(res, start, size);
994 write_unlock(&resource_lock);
995 return result;
996}
997EXPORT_SYMBOL(adjust_resource);
998
999static void __init __reserve_region_with_split(struct resource *root,
1000 resource_size_t start, resource_size_t end,
1001 const char *name)
1002{
1003 struct resource *parent = root;
1004 struct resource *conflict;
1005 struct resource *res = alloc_resource(GFP_ATOMIC);
1006 struct resource *next_res = NULL;
1007
1008 if (!res)
1009 return;
1010
1011 res->name = name;
1012 res->start = start;
1013 res->end = end;
1014 res->flags = IORESOURCE_BUSY;
1015 res->desc = IORES_DESC_NONE;
1016
1017 while (1) {
1018
1019 conflict = __request_resource(parent, res);
1020 if (!conflict) {
1021 if (!next_res)
1022 break;
1023 res = next_res;
1024 next_res = NULL;
1025 continue;
1026 }
1027
1028 /* conflict covered whole area */
1029 if (conflict->start <= res->start &&
1030 conflict->end >= res->end) {
1031 free_resource(res);
1032 WARN_ON(next_res);
1033 break;
1034 }
1035
1036 /* failed, split and try again */
1037 if (conflict->start > res->start) {
1038 end = res->end;
1039 res->end = conflict->start - 1;
1040 if (conflict->end < end) {
1041 next_res = alloc_resource(GFP_ATOMIC);
1042 if (!next_res) {
1043 free_resource(res);
1044 break;
1045 }
1046 next_res->name = name;
1047 next_res->start = conflict->end + 1;
1048 next_res->end = end;
1049 next_res->flags = IORESOURCE_BUSY;
1050 next_res->desc = IORES_DESC_NONE;
1051 }
1052 } else {
1053 res->start = conflict->end + 1;
1054 }
1055 }
1056
1057}
1058
1059void __init reserve_region_with_split(struct resource *root,
1060 resource_size_t start, resource_size_t end,
1061 const char *name)
1062{
1063 int abort = 0;
1064
1065 write_lock(&resource_lock);
1066 if (root->start > start || root->end < end) {
1067 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1068 (unsigned long long)start, (unsigned long long)end,
1069 root);
1070 if (start > root->end || end < root->start)
1071 abort = 1;
1072 else {
1073 if (end > root->end)
1074 end = root->end;
1075 if (start < root->start)
1076 start = root->start;
1077 pr_err("fixing request to [0x%llx-0x%llx]\n",
1078 (unsigned long long)start,
1079 (unsigned long long)end);
1080 }
1081 dump_stack();
1082 }
1083 if (!abort)
1084 __reserve_region_with_split(root, start, end, name);
1085 write_unlock(&resource_lock);
1086}
1087
1088/**
1089 * resource_alignment - calculate resource's alignment
1090 * @res: resource pointer
1091 *
1092 * Returns alignment on success, 0 (invalid alignment) on failure.
1093 */
1094resource_size_t resource_alignment(struct resource *res)
1095{
1096 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1097 case IORESOURCE_SIZEALIGN:
1098 return resource_size(res);
1099 case IORESOURCE_STARTALIGN:
1100 return res->start;
1101 default:
1102 return 0;
1103 }
1104}
1105
1106/*
1107 * This is compatibility stuff for IO resources.
1108 *
1109 * Note how this, unlike the above, knows about
1110 * the IO flag meanings (busy etc).
1111 *
1112 * request_region creates a new busy region.
1113 *
1114 * release_region releases a matching busy region.
1115 */
1116
1117static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1118
1119/**
1120 * __request_region - create a new busy resource region
1121 * @parent: parent resource descriptor
1122 * @start: resource start address
1123 * @n: resource region size
1124 * @name: reserving caller's ID string
1125 * @flags: IO resource flags
1126 */
1127struct resource * __request_region(struct resource *parent,
1128 resource_size_t start, resource_size_t n,
1129 const char *name, int flags)
1130{
1131 DECLARE_WAITQUEUE(wait, current);
1132 struct resource *res = alloc_resource(GFP_KERNEL);
1133
1134 if (!res)
1135 return NULL;
1136
1137 res->name = name;
1138 res->start = start;
1139 res->end = start + n - 1;
1140
1141 write_lock(&resource_lock);
1142
1143 for (;;) {
1144 struct resource *conflict;
1145
1146 res->flags = resource_type(parent) | resource_ext_type(parent);
1147 res->flags |= IORESOURCE_BUSY | flags;
1148 res->desc = parent->desc;
1149
1150 conflict = __request_resource(parent, res);
1151 if (!conflict)
1152 break;
1153 if (conflict != parent) {
1154 if (!(conflict->flags & IORESOURCE_BUSY)) {
1155 parent = conflict;
1156 continue;
1157 }
1158 }
1159 if (conflict->flags & flags & IORESOURCE_MUXED) {
1160 add_wait_queue(&muxed_resource_wait, &wait);
1161 write_unlock(&resource_lock);
1162 set_current_state(TASK_UNINTERRUPTIBLE);
1163 schedule();
1164 remove_wait_queue(&muxed_resource_wait, &wait);
1165 write_lock(&resource_lock);
1166 continue;
1167 }
1168 /* Uhhuh, that didn't work out.. */
1169 free_resource(res);
1170 res = NULL;
1171 break;
1172 }
1173 write_unlock(&resource_lock);
1174 return res;
1175}
1176EXPORT_SYMBOL(__request_region);
1177
1178/**
1179 * __release_region - release a previously reserved resource region
1180 * @parent: parent resource descriptor
1181 * @start: resource start address
1182 * @n: resource region size
1183 *
1184 * The described resource region must match a currently busy region.
1185 */
1186void __release_region(struct resource *parent, resource_size_t start,
1187 resource_size_t n)
1188{
1189 struct resource **p;
1190 resource_size_t end;
1191
1192 p = &parent->child;
1193 end = start + n - 1;
1194
1195 write_lock(&resource_lock);
1196
1197 for (;;) {
1198 struct resource *res = *p;
1199
1200 if (!res)
1201 break;
1202 if (res->start <= start && res->end >= end) {
1203 if (!(res->flags & IORESOURCE_BUSY)) {
1204 p = &res->child;
1205 continue;
1206 }
1207 if (res->start != start || res->end != end)
1208 break;
1209 *p = res->sibling;
1210 write_unlock(&resource_lock);
1211 if (res->flags & IORESOURCE_MUXED)
1212 wake_up(&muxed_resource_wait);
1213 free_resource(res);
1214 return;
1215 }
1216 p = &res->sibling;
1217 }
1218
1219 write_unlock(&resource_lock);
1220
1221 printk(KERN_WARNING "Trying to free nonexistent resource "
1222 "<%016llx-%016llx>\n", (unsigned long long)start,
1223 (unsigned long long)end);
1224}
1225EXPORT_SYMBOL(__release_region);
1226
1227#ifdef CONFIG_MEMORY_HOTREMOVE
1228/**
1229 * release_mem_region_adjustable - release a previously reserved memory region
1230 * @parent: parent resource descriptor
1231 * @start: resource start address
1232 * @size: resource region size
1233 *
1234 * This interface is intended for memory hot-delete. The requested region
1235 * is released from a currently busy memory resource. The requested region
1236 * must either match exactly or fit into a single busy resource entry. In
1237 * the latter case, the remaining resource is adjusted accordingly.
1238 * Existing children of the busy memory resource must be immutable in the
1239 * request.
1240 *
1241 * Note:
1242 * - Additional release conditions, such as overlapping region, can be
1243 * supported after they are confirmed as valid cases.
1244 * - When a busy memory resource gets split into two entries, the code
1245 * assumes that all children remain in the lower address entry for
1246 * simplicity. Enhance this logic when necessary.
1247 */
1248int release_mem_region_adjustable(struct resource *parent,
1249 resource_size_t start, resource_size_t size)
1250{
1251 struct resource **p;
1252 struct resource *res;
1253 struct resource *new_res;
1254 resource_size_t end;
1255 int ret = -EINVAL;
1256
1257 end = start + size - 1;
1258 if ((start < parent->start) || (end > parent->end))
1259 return ret;
1260
1261 /* The alloc_resource() result gets checked later */
1262 new_res = alloc_resource(GFP_KERNEL);
1263
1264 p = &parent->child;
1265 write_lock(&resource_lock);
1266
1267 while ((res = *p)) {
1268 if (res->start >= end)
1269 break;
1270
1271 /* look for the next resource if it does not fit into */
1272 if (res->start > start || res->end < end) {
1273 p = &res->sibling;
1274 continue;
1275 }
1276
1277 if (!(res->flags & IORESOURCE_MEM))
1278 break;
1279
1280 if (!(res->flags & IORESOURCE_BUSY)) {
1281 p = &res->child;
1282 continue;
1283 }
1284
1285 /* found the target resource; let's adjust accordingly */
1286 if (res->start == start && res->end == end) {
1287 /* free the whole entry */
1288 *p = res->sibling;
1289 free_resource(res);
1290 ret = 0;
1291 } else if (res->start == start && res->end != end) {
1292 /* adjust the start */
1293 ret = __adjust_resource(res, end + 1,
1294 res->end - end);
1295 } else if (res->start != start && res->end == end) {
1296 /* adjust the end */
1297 ret = __adjust_resource(res, res->start,
1298 start - res->start);
1299 } else {
1300 /* split into two entries */
1301 if (!new_res) {
1302 ret = -ENOMEM;
1303 break;
1304 }
1305 new_res->name = res->name;
1306 new_res->start = end + 1;
1307 new_res->end = res->end;
1308 new_res->flags = res->flags;
1309 new_res->desc = res->desc;
1310 new_res->parent = res->parent;
1311 new_res->sibling = res->sibling;
1312 new_res->child = NULL;
1313
1314 ret = __adjust_resource(res, res->start,
1315 start - res->start);
1316 if (ret)
1317 break;
1318 res->sibling = new_res;
1319 new_res = NULL;
1320 }
1321
1322 break;
1323 }
1324
1325 write_unlock(&resource_lock);
1326 free_resource(new_res);
1327 return ret;
1328}
1329#endif /* CONFIG_MEMORY_HOTREMOVE */
1330
1331/*
1332 * Managed region resource
1333 */
1334static void devm_resource_release(struct device *dev, void *ptr)
1335{
1336 struct resource **r = ptr;
1337
1338 release_resource(*r);
1339}
1340
1341/**
1342 * devm_request_resource() - request and reserve an I/O or memory resource
1343 * @dev: device for which to request the resource
1344 * @root: root of the resource tree from which to request the resource
1345 * @new: descriptor of the resource to request
1346 *
1347 * This is a device-managed version of request_resource(). There is usually
1348 * no need to release resources requested by this function explicitly since
1349 * that will be taken care of when the device is unbound from its driver.
1350 * If for some reason the resource needs to be released explicitly, because
1351 * of ordering issues for example, drivers must call devm_release_resource()
1352 * rather than the regular release_resource().
1353 *
1354 * When a conflict is detected between any existing resources and the newly
1355 * requested resource, an error message will be printed.
1356 *
1357 * Returns 0 on success or a negative error code on failure.
1358 */
1359int devm_request_resource(struct device *dev, struct resource *root,
1360 struct resource *new)
1361{
1362 struct resource *conflict, **ptr;
1363
1364 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1365 if (!ptr)
1366 return -ENOMEM;
1367
1368 *ptr = new;
1369
1370 conflict = request_resource_conflict(root, new);
1371 if (conflict) {
1372 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1373 new, conflict->name, conflict);
1374 devres_free(ptr);
1375 return -EBUSY;
1376 }
1377
1378 devres_add(dev, ptr);
1379 return 0;
1380}
1381EXPORT_SYMBOL(devm_request_resource);
1382
1383static int devm_resource_match(struct device *dev, void *res, void *data)
1384{
1385 struct resource **ptr = res;
1386
1387 return *ptr == data;
1388}
1389
1390/**
1391 * devm_release_resource() - release a previously requested resource
1392 * @dev: device for which to release the resource
1393 * @new: descriptor of the resource to release
1394 *
1395 * Releases a resource previously requested using devm_request_resource().
1396 */
1397void devm_release_resource(struct device *dev, struct resource *new)
1398{
1399 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1400 new));
1401}
1402EXPORT_SYMBOL(devm_release_resource);
1403
1404struct region_devres {
1405 struct resource *parent;
1406 resource_size_t start;
1407 resource_size_t n;
1408};
1409
1410static void devm_region_release(struct device *dev, void *res)
1411{
1412 struct region_devres *this = res;
1413
1414 __release_region(this->parent, this->start, this->n);
1415}
1416
1417static int devm_region_match(struct device *dev, void *res, void *match_data)
1418{
1419 struct region_devres *this = res, *match = match_data;
1420
1421 return this->parent == match->parent &&
1422 this->start == match->start && this->n == match->n;
1423}
1424
1425struct resource * __devm_request_region(struct device *dev,
1426 struct resource *parent, resource_size_t start,
1427 resource_size_t n, const char *name)
1428{
1429 struct region_devres *dr = NULL;
1430 struct resource *res;
1431
1432 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1433 GFP_KERNEL);
1434 if (!dr)
1435 return NULL;
1436
1437 dr->parent = parent;
1438 dr->start = start;
1439 dr->n = n;
1440
1441 res = __request_region(parent, start, n, name, 0);
1442 if (res)
1443 devres_add(dev, dr);
1444 else
1445 devres_free(dr);
1446
1447 return res;
1448}
1449EXPORT_SYMBOL(__devm_request_region);
1450
1451void __devm_release_region(struct device *dev, struct resource *parent,
1452 resource_size_t start, resource_size_t n)
1453{
1454 struct region_devres match_data = { parent, start, n };
1455
1456 __release_region(parent, start, n);
1457 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1458 &match_data));
1459}
1460EXPORT_SYMBOL(__devm_release_region);
1461
1462/*
1463 * Called from init/main.c to reserve IO ports.
1464 */
1465#define MAXRESERVE 4
1466static int __init reserve_setup(char *str)
1467{
1468 static int reserved;
1469 static struct resource reserve[MAXRESERVE];
1470
1471 for (;;) {
1472 unsigned int io_start, io_num;
1473 int x = reserved;
1474
1475 if (get_option (&str, &io_start) != 2)
1476 break;
1477 if (get_option (&str, &io_num) == 0)
1478 break;
1479 if (x < MAXRESERVE) {
1480 struct resource *res = reserve + x;
1481 res->name = "reserved";
1482 res->start = io_start;
1483 res->end = io_start + io_num - 1;
1484 res->flags = IORESOURCE_BUSY;
1485 res->desc = IORES_DESC_NONE;
1486 res->child = NULL;
1487 if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
1488 reserved = x+1;
1489 }
1490 }
1491 return 1;
1492}
1493
1494__setup("reserve=", reserve_setup);
1495
1496/*
1497 * Check if the requested addr and size spans more than any slot in the
1498 * iomem resource tree.
1499 */
1500int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1501{
1502 struct resource *p = &iomem_resource;
1503 int err = 0;
1504 loff_t l;
1505
1506 read_lock(&resource_lock);
1507 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1508 /*
1509 * We can probably skip the resources without
1510 * IORESOURCE_IO attribute?
1511 */
1512 if (p->start >= addr + size)
1513 continue;
1514 if (p->end < addr)
1515 continue;
1516 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1517 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1518 continue;
1519 /*
1520 * if a resource is "BUSY", it's not a hardware resource
1521 * but a driver mapping of such a resource; we don't want
1522 * to warn for those; some drivers legitimately map only
1523 * partial hardware resources. (example: vesafb)
1524 */
1525 if (p->flags & IORESOURCE_BUSY)
1526 continue;
1527
1528 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1529 (unsigned long long)addr,
1530 (unsigned long long)(addr + size - 1),
1531 p->name, p);
1532 err = -1;
1533 break;
1534 }
1535 read_unlock(&resource_lock);
1536
1537 return err;
1538}
1539
1540#ifdef CONFIG_STRICT_DEVMEM
1541static int strict_iomem_checks = 1;
1542#else
1543static int strict_iomem_checks;
1544#endif
1545
1546/*
1547 * check if an address is reserved in the iomem resource tree
1548 * returns 1 if reserved, 0 if not reserved.
1549 */
1550int iomem_is_exclusive(u64 addr)
1551{
1552 struct resource *p = &iomem_resource;
1553 int err = 0;
1554 loff_t l;
1555 int size = PAGE_SIZE;
1556
1557 if (!strict_iomem_checks)
1558 return 0;
1559
1560 addr = addr & PAGE_MASK;
1561
1562 read_lock(&resource_lock);
1563 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1564 /*
1565 * We can probably skip the resources without
1566 * IORESOURCE_IO attribute?
1567 */
1568 if (p->start >= addr + size)
1569 break;
1570 if (p->end < addr)
1571 continue;
1572 /*
1573 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1574 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1575 * resource is busy.
1576 */
1577 if ((p->flags & IORESOURCE_BUSY) == 0)
1578 continue;
1579 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1580 || p->flags & IORESOURCE_EXCLUSIVE) {
1581 err = 1;
1582 break;
1583 }
1584 }
1585 read_unlock(&resource_lock);
1586
1587 return err;
1588}
1589
1590struct resource_entry *resource_list_create_entry(struct resource *res,
1591 size_t extra_size)
1592{
1593 struct resource_entry *entry;
1594
1595 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1596 if (entry) {
1597 INIT_LIST_HEAD(&entry->node);
1598 entry->res = res ? res : &entry->__res;
1599 }
1600
1601 return entry;
1602}
1603EXPORT_SYMBOL(resource_list_create_entry);
1604
1605void resource_list_free(struct list_head *head)
1606{
1607 struct resource_entry *entry, *tmp;
1608
1609 list_for_each_entry_safe(entry, tmp, head, node)
1610 resource_list_destroy_entry(entry);
1611}
1612EXPORT_SYMBOL(resource_list_free);
1613
1614static int __init strict_iomem(char *str)
1615{
1616 if (strstr(str, "relaxed"))
1617 strict_iomem_checks = 0;
1618 if (strstr(str, "strict"))
1619 strict_iomem_checks = 1;
1620 return 1;
1621}
1622
1623__setup("iomem=", strict_iomem);
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 <asm/io.h>
31
32
33struct resource ioport_resource = {
34 .name = "PCI IO",
35 .start = 0,
36 .end = IO_SPACE_LIMIT,
37 .flags = IORESOURCE_IO,
38};
39EXPORT_SYMBOL(ioport_resource);
40
41struct resource iomem_resource = {
42 .name = "PCI mem",
43 .start = 0,
44 .end = -1,
45 .flags = IORESOURCE_MEM,
46};
47EXPORT_SYMBOL(iomem_resource);
48
49/* constraints to be met while allocating resources */
50struct resource_constraint {
51 resource_size_t min, max, align;
52 resource_size_t (*alignf)(void *, const struct resource *,
53 resource_size_t, resource_size_t);
54 void *alignf_data;
55};
56
57static DEFINE_RWLOCK(resource_lock);
58
59static struct resource *next_resource(struct resource *p)
60{
61 if (p->child)
62 return p->child;
63 while (!p->sibling && p->parent)
64 p = p->parent;
65 return p->sibling;
66}
67
68static struct resource *next_resource_skip_children(struct resource *p)
69{
70 while (!p->sibling && p->parent)
71 p = p->parent;
72 return p->sibling;
73}
74
75#define for_each_resource(_root, _p, _skip_children) \
76 for ((_p) = (_root)->child; (_p); \
77 (_p) = (_skip_children) ? next_resource_skip_children(_p) : \
78 next_resource(_p))
79
80static void *r_next(struct seq_file *m, void *v, loff_t *pos)
81{
82 struct resource *p = v;
83 (*pos)++;
84 return (void *)next_resource(p);
85}
86
87#ifdef CONFIG_PROC_FS
88
89enum { MAX_IORES_LEVEL = 5 };
90
91static void *r_start(struct seq_file *m, loff_t *pos)
92 __acquires(resource_lock)
93{
94 struct resource *p = pde_data(file_inode(m->file));
95 loff_t l = 0;
96 read_lock(&resource_lock);
97 for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
98 ;
99 return p;
100}
101
102static void r_stop(struct seq_file *m, void *v)
103 __releases(resource_lock)
104{
105 read_unlock(&resource_lock);
106}
107
108static int r_show(struct seq_file *m, void *v)
109{
110 struct resource *root = pde_data(file_inode(m->file));
111 struct resource *r = v, *p;
112 unsigned long long start, end;
113 int width = root->end < 0x10000 ? 4 : 8;
114 int depth;
115
116 for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
117 if (p->parent == root)
118 break;
119
120 if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
121 start = r->start;
122 end = r->end;
123 } else {
124 start = end = 0;
125 }
126
127 seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
128 depth * 2, "",
129 width, start,
130 width, end,
131 r->name ? r->name : "<BAD>");
132 return 0;
133}
134
135static const struct seq_operations resource_op = {
136 .start = r_start,
137 .next = r_next,
138 .stop = r_stop,
139 .show = r_show,
140};
141
142static int __init ioresources_init(void)
143{
144 proc_create_seq_data("ioports", 0, NULL, &resource_op,
145 &ioport_resource);
146 proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource);
147 return 0;
148}
149__initcall(ioresources_init);
150
151#endif /* CONFIG_PROC_FS */
152
153static void free_resource(struct resource *res)
154{
155 /**
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 (p = iomem_resource.child; p; p = next_resource(p)) {
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 calls the @func callback against all memory ranges, which
436 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
437 */
438int walk_mem_res(u64 start, u64 end, void *arg,
439 int (*func)(struct resource *, void *))
440{
441 unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
442
443 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
444 func);
445}
446
447/*
448 * This function calls the @func callback against all memory ranges of type
449 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
450 * It is to be used only for System RAM.
451 */
452int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
453 void *arg, int (*func)(unsigned long, unsigned long, void *))
454{
455 resource_size_t start, end;
456 unsigned long flags;
457 struct resource res;
458 unsigned long pfn, end_pfn;
459 int ret = -EINVAL;
460
461 start = (u64) start_pfn << PAGE_SHIFT;
462 end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
463 flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
464 while (start < end &&
465 !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res)) {
466 pfn = PFN_UP(res.start);
467 end_pfn = PFN_DOWN(res.end + 1);
468 if (end_pfn > pfn)
469 ret = (*func)(pfn, end_pfn - pfn, arg);
470 if (ret)
471 break;
472 start = res.end + 1;
473 }
474 return ret;
475}
476
477static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
478{
479 return 1;
480}
481
482/*
483 * This generic page_is_ram() returns true if specified address is
484 * registered as System RAM in iomem_resource list.
485 */
486int __weak page_is_ram(unsigned long pfn)
487{
488 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
489}
490EXPORT_SYMBOL_GPL(page_is_ram);
491
492static int __region_intersects(struct resource *parent, resource_size_t start,
493 size_t size, unsigned long flags,
494 unsigned long desc)
495{
496 struct resource res;
497 int type = 0; int other = 0;
498 struct resource *p;
499
500 res.start = start;
501 res.end = start + size - 1;
502
503 for (p = parent->child; p ; p = p->sibling) {
504 bool is_type = (((p->flags & flags) == flags) &&
505 ((desc == IORES_DESC_NONE) ||
506 (desc == p->desc)));
507
508 if (resource_overlaps(p, &res))
509 is_type ? type++ : other++;
510 }
511
512 if (type == 0)
513 return REGION_DISJOINT;
514
515 if (other == 0)
516 return REGION_INTERSECTS;
517
518 return REGION_MIXED;
519}
520
521/**
522 * region_intersects() - determine intersection of region with known resources
523 * @start: region start address
524 * @size: size of region
525 * @flags: flags of resource (in iomem_resource)
526 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
527 *
528 * Check if the specified region partially overlaps or fully eclipses a
529 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
530 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
531 * return REGION_MIXED if the region overlaps @flags/@desc and another
532 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
533 * and no other defined resource. Note that REGION_INTERSECTS is also
534 * returned in the case when the specified region overlaps RAM and undefined
535 * memory holes.
536 *
537 * region_intersect() is used by memory remapping functions to ensure
538 * the user is not remapping RAM and is a vast speed up over walking
539 * through the resource table page by page.
540 */
541int region_intersects(resource_size_t start, size_t size, unsigned long flags,
542 unsigned long desc)
543{
544 int ret;
545
546 read_lock(&resource_lock);
547 ret = __region_intersects(&iomem_resource, start, size, flags, desc);
548 read_unlock(&resource_lock);
549
550 return ret;
551}
552EXPORT_SYMBOL_GPL(region_intersects);
553
554void __weak arch_remove_reservations(struct resource *avail)
555{
556}
557
558static resource_size_t simple_align_resource(void *data,
559 const struct resource *avail,
560 resource_size_t size,
561 resource_size_t align)
562{
563 return avail->start;
564}
565
566static void resource_clip(struct resource *res, resource_size_t min,
567 resource_size_t max)
568{
569 if (res->start < min)
570 res->start = min;
571 if (res->end > max)
572 res->end = max;
573}
574
575/*
576 * Find empty slot in the resource tree with the given range and
577 * alignment constraints
578 */
579static int __find_resource(struct resource *root, struct resource *old,
580 struct resource *new,
581 resource_size_t size,
582 struct resource_constraint *constraint)
583{
584 struct resource *this = root->child;
585 struct resource tmp = *new, avail, alloc;
586
587 tmp.start = root->start;
588 /*
589 * Skip past an allocated resource that starts at 0, since the assignment
590 * of this->start - 1 to tmp->end below would cause an underflow.
591 */
592 if (this && this->start == root->start) {
593 tmp.start = (this == old) ? old->start : this->end + 1;
594 this = this->sibling;
595 }
596 for(;;) {
597 if (this)
598 tmp.end = (this == old) ? this->end : this->start - 1;
599 else
600 tmp.end = root->end;
601
602 if (tmp.end < tmp.start)
603 goto next;
604
605 resource_clip(&tmp, constraint->min, constraint->max);
606 arch_remove_reservations(&tmp);
607
608 /* Check for overflow after ALIGN() */
609 avail.start = ALIGN(tmp.start, constraint->align);
610 avail.end = tmp.end;
611 avail.flags = new->flags & ~IORESOURCE_UNSET;
612 if (avail.start >= tmp.start) {
613 alloc.flags = avail.flags;
614 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
615 size, constraint->align);
616 alloc.end = alloc.start + size - 1;
617 if (alloc.start <= alloc.end &&
618 resource_contains(&avail, &alloc)) {
619 new->start = alloc.start;
620 new->end = alloc.end;
621 return 0;
622 }
623 }
624
625next: if (!this || this->end == root->end)
626 break;
627
628 if (this != old)
629 tmp.start = this->end + 1;
630 this = this->sibling;
631 }
632 return -EBUSY;
633}
634
635/*
636 * Find empty slot in the resource tree given range and alignment.
637 */
638static int find_resource(struct resource *root, struct resource *new,
639 resource_size_t size,
640 struct resource_constraint *constraint)
641{
642 return __find_resource(root, NULL, new, size, constraint);
643}
644
645/**
646 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
647 * The resource will be relocated if the new size cannot be reallocated in the
648 * current location.
649 *
650 * @root: root resource descriptor
651 * @old: resource descriptor desired by caller
652 * @newsize: new size of the resource descriptor
653 * @constraint: the size and alignment constraints to be met.
654 */
655static int reallocate_resource(struct resource *root, struct resource *old,
656 resource_size_t newsize,
657 struct resource_constraint *constraint)
658{
659 int err=0;
660 struct resource new = *old;
661 struct resource *conflict;
662
663 write_lock(&resource_lock);
664
665 if ((err = __find_resource(root, old, &new, newsize, constraint)))
666 goto out;
667
668 if (resource_contains(&new, old)) {
669 old->start = new.start;
670 old->end = new.end;
671 goto out;
672 }
673
674 if (old->child) {
675 err = -EBUSY;
676 goto out;
677 }
678
679 if (resource_contains(old, &new)) {
680 old->start = new.start;
681 old->end = new.end;
682 } else {
683 __release_resource(old, true);
684 *old = new;
685 conflict = __request_resource(root, old);
686 BUG_ON(conflict);
687 }
688out:
689 write_unlock(&resource_lock);
690 return err;
691}
692
693
694/**
695 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
696 * The resource will be reallocated with a new size if it was already allocated
697 * @root: root resource descriptor
698 * @new: resource descriptor desired by caller
699 * @size: requested resource region size
700 * @min: minimum boundary to allocate
701 * @max: maximum boundary to allocate
702 * @align: alignment requested, in bytes
703 * @alignf: alignment function, optional, called if not NULL
704 * @alignf_data: arbitrary data to pass to the @alignf function
705 */
706int allocate_resource(struct resource *root, struct resource *new,
707 resource_size_t size, resource_size_t min,
708 resource_size_t max, resource_size_t align,
709 resource_size_t (*alignf)(void *,
710 const struct resource *,
711 resource_size_t,
712 resource_size_t),
713 void *alignf_data)
714{
715 int err;
716 struct resource_constraint constraint;
717
718 if (!alignf)
719 alignf = simple_align_resource;
720
721 constraint.min = min;
722 constraint.max = max;
723 constraint.align = align;
724 constraint.alignf = alignf;
725 constraint.alignf_data = alignf_data;
726
727 if ( new->parent ) {
728 /* resource is already allocated, try reallocating with
729 the new constraints */
730 return reallocate_resource(root, new, size, &constraint);
731 }
732
733 write_lock(&resource_lock);
734 err = find_resource(root, new, size, &constraint);
735 if (err >= 0 && __request_resource(root, new))
736 err = -EBUSY;
737 write_unlock(&resource_lock);
738 return err;
739}
740
741EXPORT_SYMBOL(allocate_resource);
742
743/**
744 * lookup_resource - find an existing resource by a resource start address
745 * @root: root resource descriptor
746 * @start: resource start address
747 *
748 * Returns a pointer to the resource if found, NULL otherwise
749 */
750struct resource *lookup_resource(struct resource *root, resource_size_t start)
751{
752 struct resource *res;
753
754 read_lock(&resource_lock);
755 for (res = root->child; res; res = res->sibling) {
756 if (res->start == start)
757 break;
758 }
759 read_unlock(&resource_lock);
760
761 return res;
762}
763
764/*
765 * Insert a resource into the resource tree. If successful, return NULL,
766 * otherwise return the conflicting resource (compare to __request_resource())
767 */
768static struct resource * __insert_resource(struct resource *parent, struct resource *new)
769{
770 struct resource *first, *next;
771
772 for (;; parent = first) {
773 first = __request_resource(parent, new);
774 if (!first)
775 return first;
776
777 if (first == parent)
778 return first;
779 if (WARN_ON(first == new)) /* duplicated insertion */
780 return first;
781
782 if ((first->start > new->start) || (first->end < new->end))
783 break;
784 if ((first->start == new->start) && (first->end == new->end))
785 break;
786 }
787
788 for (next = first; ; next = next->sibling) {
789 /* Partial overlap? Bad, and unfixable */
790 if (next->start < new->start || next->end > new->end)
791 return next;
792 if (!next->sibling)
793 break;
794 if (next->sibling->start > new->end)
795 break;
796 }
797
798 new->parent = parent;
799 new->sibling = next->sibling;
800 new->child = first;
801
802 next->sibling = NULL;
803 for (next = first; next; next = next->sibling)
804 next->parent = new;
805
806 if (parent->child == first) {
807 parent->child = new;
808 } else {
809 next = parent->child;
810 while (next->sibling != first)
811 next = next->sibling;
812 next->sibling = new;
813 }
814 return NULL;
815}
816
817/**
818 * insert_resource_conflict - Inserts resource in the resource tree
819 * @parent: parent of the new resource
820 * @new: new resource to insert
821 *
822 * Returns 0 on success, conflict resource if the resource can't be inserted.
823 *
824 * This function is equivalent to request_resource_conflict when no conflict
825 * happens. If a conflict happens, and the conflicting resources
826 * entirely fit within the range of the new resource, then the new
827 * resource is inserted and the conflicting resources become children of
828 * the new resource.
829 *
830 * This function is intended for producers of resources, such as FW modules
831 * and bus drivers.
832 */
833struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
834{
835 struct resource *conflict;
836
837 write_lock(&resource_lock);
838 conflict = __insert_resource(parent, new);
839 write_unlock(&resource_lock);
840 return conflict;
841}
842
843/**
844 * insert_resource - Inserts a resource in the resource tree
845 * @parent: parent of the new resource
846 * @new: new resource to insert
847 *
848 * Returns 0 on success, -EBUSY if the resource can't be inserted.
849 *
850 * This function is intended for producers of resources, such as FW modules
851 * and bus drivers.
852 */
853int insert_resource(struct resource *parent, struct resource *new)
854{
855 struct resource *conflict;
856
857 conflict = insert_resource_conflict(parent, new);
858 return conflict ? -EBUSY : 0;
859}
860EXPORT_SYMBOL_GPL(insert_resource);
861
862/**
863 * insert_resource_expand_to_fit - Insert a resource into the resource tree
864 * @root: root resource descriptor
865 * @new: new resource to insert
866 *
867 * Insert a resource into the resource tree, possibly expanding it in order
868 * to make it encompass any conflicting resources.
869 */
870void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
871{
872 if (new->parent)
873 return;
874
875 write_lock(&resource_lock);
876 for (;;) {
877 struct resource *conflict;
878
879 conflict = __insert_resource(root, new);
880 if (!conflict)
881 break;
882 if (conflict == root)
883 break;
884
885 /* Ok, expand resource to cover the conflict, then try again .. */
886 if (conflict->start < new->start)
887 new->start = conflict->start;
888 if (conflict->end > new->end)
889 new->end = conflict->end;
890
891 pr_info("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
892 }
893 write_unlock(&resource_lock);
894}
895/*
896 * Not for general consumption, only early boot memory map parsing, PCI
897 * resource discovery, and late discovery of CXL resources are expected
898 * to use this interface. The former are built-in and only the latter,
899 * CXL, is a module.
900 */
901EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit, CXL);
902
903/**
904 * remove_resource - Remove a resource in the resource tree
905 * @old: resource to remove
906 *
907 * Returns 0 on success, -EINVAL if the resource is not valid.
908 *
909 * This function removes a resource previously inserted by insert_resource()
910 * or insert_resource_conflict(), and moves the children (if any) up to
911 * where they were before. insert_resource() and insert_resource_conflict()
912 * insert a new resource, and move any conflicting resources down to the
913 * children of the new resource.
914 *
915 * insert_resource(), insert_resource_conflict() and remove_resource() are
916 * intended for producers of resources, such as FW modules and bus drivers.
917 */
918int remove_resource(struct resource *old)
919{
920 int retval;
921
922 write_lock(&resource_lock);
923 retval = __release_resource(old, false);
924 write_unlock(&resource_lock);
925 return retval;
926}
927EXPORT_SYMBOL_GPL(remove_resource);
928
929static int __adjust_resource(struct resource *res, resource_size_t start,
930 resource_size_t size)
931{
932 struct resource *tmp, *parent = res->parent;
933 resource_size_t end = start + size - 1;
934 int result = -EBUSY;
935
936 if (!parent)
937 goto skip;
938
939 if ((start < parent->start) || (end > parent->end))
940 goto out;
941
942 if (res->sibling && (res->sibling->start <= end))
943 goto out;
944
945 tmp = parent->child;
946 if (tmp != res) {
947 while (tmp->sibling != res)
948 tmp = tmp->sibling;
949 if (start <= tmp->end)
950 goto out;
951 }
952
953skip:
954 for (tmp = res->child; tmp; tmp = tmp->sibling)
955 if ((tmp->start < start) || (tmp->end > end))
956 goto out;
957
958 res->start = start;
959 res->end = end;
960 result = 0;
961
962 out:
963 return result;
964}
965
966/**
967 * adjust_resource - modify a resource's start and size
968 * @res: resource to modify
969 * @start: new start value
970 * @size: new size
971 *
972 * Given an existing resource, change its start and size to match the
973 * arguments. Returns 0 on success, -EBUSY if it can't fit.
974 * Existing children of the resource are assumed to be immutable.
975 */
976int adjust_resource(struct resource *res, resource_size_t start,
977 resource_size_t size)
978{
979 int result;
980
981 write_lock(&resource_lock);
982 result = __adjust_resource(res, start, size);
983 write_unlock(&resource_lock);
984 return result;
985}
986EXPORT_SYMBOL(adjust_resource);
987
988static void __init
989__reserve_region_with_split(struct resource *root, resource_size_t start,
990 resource_size_t end, const char *name)
991{
992 struct resource *parent = root;
993 struct resource *conflict;
994 struct resource *res = alloc_resource(GFP_ATOMIC);
995 struct resource *next_res = NULL;
996 int type = resource_type(root);
997
998 if (!res)
999 return;
1000
1001 res->name = name;
1002 res->start = start;
1003 res->end = end;
1004 res->flags = type | IORESOURCE_BUSY;
1005 res->desc = IORES_DESC_NONE;
1006
1007 while (1) {
1008
1009 conflict = __request_resource(parent, res);
1010 if (!conflict) {
1011 if (!next_res)
1012 break;
1013 res = next_res;
1014 next_res = NULL;
1015 continue;
1016 }
1017
1018 /* conflict covered whole area */
1019 if (conflict->start <= res->start &&
1020 conflict->end >= res->end) {
1021 free_resource(res);
1022 WARN_ON(next_res);
1023 break;
1024 }
1025
1026 /* failed, split and try again */
1027 if (conflict->start > res->start) {
1028 end = res->end;
1029 res->end = conflict->start - 1;
1030 if (conflict->end < end) {
1031 next_res = alloc_resource(GFP_ATOMIC);
1032 if (!next_res) {
1033 free_resource(res);
1034 break;
1035 }
1036 next_res->name = name;
1037 next_res->start = conflict->end + 1;
1038 next_res->end = end;
1039 next_res->flags = type | IORESOURCE_BUSY;
1040 next_res->desc = IORES_DESC_NONE;
1041 }
1042 } else {
1043 res->start = conflict->end + 1;
1044 }
1045 }
1046
1047}
1048
1049void __init
1050reserve_region_with_split(struct resource *root, resource_size_t start,
1051 resource_size_t end, const char *name)
1052{
1053 int abort = 0;
1054
1055 write_lock(&resource_lock);
1056 if (root->start > start || root->end < end) {
1057 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1058 (unsigned long long)start, (unsigned long long)end,
1059 root);
1060 if (start > root->end || end < root->start)
1061 abort = 1;
1062 else {
1063 if (end > root->end)
1064 end = root->end;
1065 if (start < root->start)
1066 start = root->start;
1067 pr_err("fixing request to [0x%llx-0x%llx]\n",
1068 (unsigned long long)start,
1069 (unsigned long long)end);
1070 }
1071 dump_stack();
1072 }
1073 if (!abort)
1074 __reserve_region_with_split(root, start, end, name);
1075 write_unlock(&resource_lock);
1076}
1077
1078/**
1079 * resource_alignment - calculate resource's alignment
1080 * @res: resource pointer
1081 *
1082 * Returns alignment on success, 0 (invalid alignment) on failure.
1083 */
1084resource_size_t resource_alignment(struct resource *res)
1085{
1086 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1087 case IORESOURCE_SIZEALIGN:
1088 return resource_size(res);
1089 case IORESOURCE_STARTALIGN:
1090 return res->start;
1091 default:
1092 return 0;
1093 }
1094}
1095
1096/*
1097 * This is compatibility stuff for IO resources.
1098 *
1099 * Note how this, unlike the above, knows about
1100 * the IO flag meanings (busy etc).
1101 *
1102 * request_region creates a new busy region.
1103 *
1104 * release_region releases a matching busy region.
1105 */
1106
1107static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1108
1109static struct inode *iomem_inode;
1110
1111#ifdef CONFIG_IO_STRICT_DEVMEM
1112static void revoke_iomem(struct resource *res)
1113{
1114 /* pairs with smp_store_release() in iomem_init_inode() */
1115 struct inode *inode = smp_load_acquire(&iomem_inode);
1116
1117 /*
1118 * Check that the initialization has completed. Losing the race
1119 * is ok because it means drivers are claiming resources before
1120 * the fs_initcall level of init and prevent iomem_get_mapping users
1121 * from establishing mappings.
1122 */
1123 if (!inode)
1124 return;
1125
1126 /*
1127 * The expectation is that the driver has successfully marked
1128 * the resource busy by this point, so devmem_is_allowed()
1129 * should start returning false, however for performance this
1130 * does not iterate the entire resource range.
1131 */
1132 if (devmem_is_allowed(PHYS_PFN(res->start)) &&
1133 devmem_is_allowed(PHYS_PFN(res->end))) {
1134 /*
1135 * *cringe* iomem=relaxed says "go ahead, what's the
1136 * worst that can happen?"
1137 */
1138 return;
1139 }
1140
1141 unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1);
1142}
1143#else
1144static void revoke_iomem(struct resource *res) {}
1145#endif
1146
1147struct address_space *iomem_get_mapping(void)
1148{
1149 /*
1150 * This function is only called from file open paths, hence guaranteed
1151 * that fs_initcalls have completed and no need to check for NULL. But
1152 * since revoke_iomem can be called before the initcall we still need
1153 * the barrier to appease checkers.
1154 */
1155 return smp_load_acquire(&iomem_inode)->i_mapping;
1156}
1157
1158static int __request_region_locked(struct resource *res, struct resource *parent,
1159 resource_size_t start, resource_size_t n,
1160 const char *name, int flags)
1161{
1162 DECLARE_WAITQUEUE(wait, current);
1163
1164 res->name = name;
1165 res->start = start;
1166 res->end = start + n - 1;
1167
1168 for (;;) {
1169 struct resource *conflict;
1170
1171 res->flags = resource_type(parent) | resource_ext_type(parent);
1172 res->flags |= IORESOURCE_BUSY | flags;
1173 res->desc = parent->desc;
1174
1175 conflict = __request_resource(parent, res);
1176 if (!conflict)
1177 break;
1178 /*
1179 * mm/hmm.c reserves physical addresses which then
1180 * become unavailable to other users. Conflicts are
1181 * not expected. Warn to aid debugging if encountered.
1182 */
1183 if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1184 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1185 conflict->name, conflict, res);
1186 }
1187 if (conflict != parent) {
1188 if (!(conflict->flags & IORESOURCE_BUSY)) {
1189 parent = conflict;
1190 continue;
1191 }
1192 }
1193 if (conflict->flags & flags & IORESOURCE_MUXED) {
1194 add_wait_queue(&muxed_resource_wait, &wait);
1195 write_unlock(&resource_lock);
1196 set_current_state(TASK_UNINTERRUPTIBLE);
1197 schedule();
1198 remove_wait_queue(&muxed_resource_wait, &wait);
1199 write_lock(&resource_lock);
1200 continue;
1201 }
1202 /* Uhhuh, that didn't work out.. */
1203 return -EBUSY;
1204 }
1205
1206 return 0;
1207}
1208
1209/**
1210 * __request_region - create a new busy resource region
1211 * @parent: parent resource descriptor
1212 * @start: resource start address
1213 * @n: resource region size
1214 * @name: reserving caller's ID string
1215 * @flags: IO resource flags
1216 */
1217struct resource *__request_region(struct resource *parent,
1218 resource_size_t start, resource_size_t n,
1219 const char *name, int flags)
1220{
1221 struct resource *res = alloc_resource(GFP_KERNEL);
1222 int ret;
1223
1224 if (!res)
1225 return NULL;
1226
1227 write_lock(&resource_lock);
1228 ret = __request_region_locked(res, parent, start, n, name, flags);
1229 write_unlock(&resource_lock);
1230
1231 if (ret) {
1232 free_resource(res);
1233 return NULL;
1234 }
1235
1236 if (parent == &iomem_resource)
1237 revoke_iomem(res);
1238
1239 return res;
1240}
1241EXPORT_SYMBOL(__request_region);
1242
1243/**
1244 * __release_region - release a previously reserved resource region
1245 * @parent: parent resource descriptor
1246 * @start: resource start address
1247 * @n: resource region size
1248 *
1249 * The described resource region must match a currently busy region.
1250 */
1251void __release_region(struct resource *parent, resource_size_t start,
1252 resource_size_t n)
1253{
1254 struct resource **p;
1255 resource_size_t end;
1256
1257 p = &parent->child;
1258 end = start + n - 1;
1259
1260 write_lock(&resource_lock);
1261
1262 for (;;) {
1263 struct resource *res = *p;
1264
1265 if (!res)
1266 break;
1267 if (res->start <= start && res->end >= end) {
1268 if (!(res->flags & IORESOURCE_BUSY)) {
1269 p = &res->child;
1270 continue;
1271 }
1272 if (res->start != start || res->end != end)
1273 break;
1274 *p = res->sibling;
1275 write_unlock(&resource_lock);
1276 if (res->flags & IORESOURCE_MUXED)
1277 wake_up(&muxed_resource_wait);
1278 free_resource(res);
1279 return;
1280 }
1281 p = &res->sibling;
1282 }
1283
1284 write_unlock(&resource_lock);
1285
1286 pr_warn("Trying to free nonexistent resource <%pa-%pa>\n", &start, &end);
1287}
1288EXPORT_SYMBOL(__release_region);
1289
1290#ifdef CONFIG_MEMORY_HOTREMOVE
1291/**
1292 * release_mem_region_adjustable - release a previously reserved memory region
1293 * @start: resource start address
1294 * @size: resource region size
1295 *
1296 * This interface is intended for memory hot-delete. The requested region
1297 * is released from a currently busy memory resource. The requested region
1298 * must either match exactly or fit into a single busy resource entry. In
1299 * the latter case, the remaining resource is adjusted accordingly.
1300 * Existing children of the busy memory resource must be immutable in the
1301 * request.
1302 *
1303 * Note:
1304 * - Additional release conditions, such as overlapping region, can be
1305 * supported after they are confirmed as valid cases.
1306 * - When a busy memory resource gets split into two entries, the code
1307 * assumes that all children remain in the lower address entry for
1308 * simplicity. Enhance this logic when necessary.
1309 */
1310void release_mem_region_adjustable(resource_size_t start, resource_size_t size)
1311{
1312 struct resource *parent = &iomem_resource;
1313 struct resource *new_res = NULL;
1314 bool alloc_nofail = false;
1315 struct resource **p;
1316 struct resource *res;
1317 resource_size_t end;
1318
1319 end = start + size - 1;
1320 if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
1321 return;
1322
1323 /*
1324 * We free up quite a lot of memory on memory hotunplug (esp., memap),
1325 * just before releasing the region. This is highly unlikely to
1326 * fail - let's play save and make it never fail as the caller cannot
1327 * perform any error handling (e.g., trying to re-add memory will fail
1328 * similarly).
1329 */
1330retry:
1331 new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
1332
1333 p = &parent->child;
1334 write_lock(&resource_lock);
1335
1336 while ((res = *p)) {
1337 if (res->start >= end)
1338 break;
1339
1340 /* look for the next resource if it does not fit into */
1341 if (res->start > start || res->end < end) {
1342 p = &res->sibling;
1343 continue;
1344 }
1345
1346 /*
1347 * All memory regions added from memory-hotplug path have the
1348 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1349 * this flag, we know that we are dealing with a resource coming
1350 * from HMM/devm. HMM/devm use another mechanism to add/release
1351 * a resource. This goes via devm_request_mem_region and
1352 * devm_release_mem_region.
1353 * HMM/devm take care to release their resources when they want,
1354 * so if we are dealing with them, let us just back off here.
1355 */
1356 if (!(res->flags & IORESOURCE_SYSRAM)) {
1357 break;
1358 }
1359
1360 if (!(res->flags & IORESOURCE_MEM))
1361 break;
1362
1363 if (!(res->flags & IORESOURCE_BUSY)) {
1364 p = &res->child;
1365 continue;
1366 }
1367
1368 /* found the target resource; let's adjust accordingly */
1369 if (res->start == start && res->end == end) {
1370 /* free the whole entry */
1371 *p = res->sibling;
1372 free_resource(res);
1373 } else if (res->start == start && res->end != end) {
1374 /* adjust the start */
1375 WARN_ON_ONCE(__adjust_resource(res, end + 1,
1376 res->end - end));
1377 } else if (res->start != start && res->end == end) {
1378 /* adjust the end */
1379 WARN_ON_ONCE(__adjust_resource(res, res->start,
1380 start - res->start));
1381 } else {
1382 /* split into two entries - we need a new resource */
1383 if (!new_res) {
1384 new_res = alloc_resource(GFP_ATOMIC);
1385 if (!new_res) {
1386 alloc_nofail = true;
1387 write_unlock(&resource_lock);
1388 goto retry;
1389 }
1390 }
1391 new_res->name = res->name;
1392 new_res->start = end + 1;
1393 new_res->end = res->end;
1394 new_res->flags = res->flags;
1395 new_res->desc = res->desc;
1396 new_res->parent = res->parent;
1397 new_res->sibling = res->sibling;
1398 new_res->child = NULL;
1399
1400 if (WARN_ON_ONCE(__adjust_resource(res, res->start,
1401 start - res->start)))
1402 break;
1403 res->sibling = new_res;
1404 new_res = NULL;
1405 }
1406
1407 break;
1408 }
1409
1410 write_unlock(&resource_lock);
1411 free_resource(new_res);
1412}
1413#endif /* CONFIG_MEMORY_HOTREMOVE */
1414
1415#ifdef CONFIG_MEMORY_HOTPLUG
1416static bool system_ram_resources_mergeable(struct resource *r1,
1417 struct resource *r2)
1418{
1419 /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1420 return r1->flags == r2->flags && r1->end + 1 == r2->start &&
1421 r1->name == r2->name && r1->desc == r2->desc &&
1422 !r1->child && !r2->child;
1423}
1424
1425/**
1426 * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1427 * merge it with adjacent, mergeable resources
1428 * @res: resource descriptor
1429 *
1430 * This interface is intended for memory hotplug, whereby lots of contiguous
1431 * system ram resources are added (e.g., via add_memory*()) by a driver, and
1432 * the actual resource boundaries are not of interest (e.g., it might be
1433 * relevant for DIMMs). Only resources that are marked mergeable, that have the
1434 * same parent, and that don't have any children are considered. All mergeable
1435 * resources must be immutable during the request.
1436 *
1437 * Note:
1438 * - The caller has to make sure that no pointers to resources that are
1439 * marked mergeable are used anymore after this call - the resource might
1440 * be freed and the pointer might be stale!
1441 * - release_mem_region_adjustable() will split on demand on memory hotunplug
1442 */
1443void merge_system_ram_resource(struct resource *res)
1444{
1445 const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
1446 struct resource *cur;
1447
1448 if (WARN_ON_ONCE((res->flags & flags) != flags))
1449 return;
1450
1451 write_lock(&resource_lock);
1452 res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
1453
1454 /* Try to merge with next item in the list. */
1455 cur = res->sibling;
1456 if (cur && system_ram_resources_mergeable(res, cur)) {
1457 res->end = cur->end;
1458 res->sibling = cur->sibling;
1459 free_resource(cur);
1460 }
1461
1462 /* Try to merge with previous item in the list. */
1463 cur = res->parent->child;
1464 while (cur && cur->sibling != res)
1465 cur = cur->sibling;
1466 if (cur && system_ram_resources_mergeable(cur, res)) {
1467 cur->end = res->end;
1468 cur->sibling = res->sibling;
1469 free_resource(res);
1470 }
1471 write_unlock(&resource_lock);
1472}
1473#endif /* CONFIG_MEMORY_HOTPLUG */
1474
1475/*
1476 * Managed region resource
1477 */
1478static void devm_resource_release(struct device *dev, void *ptr)
1479{
1480 struct resource **r = ptr;
1481
1482 release_resource(*r);
1483}
1484
1485/**
1486 * devm_request_resource() - request and reserve an I/O or memory resource
1487 * @dev: device for which to request the resource
1488 * @root: root of the resource tree from which to request the resource
1489 * @new: descriptor of the resource to request
1490 *
1491 * This is a device-managed version of request_resource(). There is usually
1492 * no need to release resources requested by this function explicitly since
1493 * that will be taken care of when the device is unbound from its driver.
1494 * If for some reason the resource needs to be released explicitly, because
1495 * of ordering issues for example, drivers must call devm_release_resource()
1496 * rather than the regular release_resource().
1497 *
1498 * When a conflict is detected between any existing resources and the newly
1499 * requested resource, an error message will be printed.
1500 *
1501 * Returns 0 on success or a negative error code on failure.
1502 */
1503int devm_request_resource(struct device *dev, struct resource *root,
1504 struct resource *new)
1505{
1506 struct resource *conflict, **ptr;
1507
1508 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1509 if (!ptr)
1510 return -ENOMEM;
1511
1512 *ptr = new;
1513
1514 conflict = request_resource_conflict(root, new);
1515 if (conflict) {
1516 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1517 new, conflict->name, conflict);
1518 devres_free(ptr);
1519 return -EBUSY;
1520 }
1521
1522 devres_add(dev, ptr);
1523 return 0;
1524}
1525EXPORT_SYMBOL(devm_request_resource);
1526
1527static int devm_resource_match(struct device *dev, void *res, void *data)
1528{
1529 struct resource **ptr = res;
1530
1531 return *ptr == data;
1532}
1533
1534/**
1535 * devm_release_resource() - release a previously requested resource
1536 * @dev: device for which to release the resource
1537 * @new: descriptor of the resource to release
1538 *
1539 * Releases a resource previously requested using devm_request_resource().
1540 */
1541void devm_release_resource(struct device *dev, struct resource *new)
1542{
1543 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1544 new));
1545}
1546EXPORT_SYMBOL(devm_release_resource);
1547
1548struct region_devres {
1549 struct resource *parent;
1550 resource_size_t start;
1551 resource_size_t n;
1552};
1553
1554static void devm_region_release(struct device *dev, void *res)
1555{
1556 struct region_devres *this = res;
1557
1558 __release_region(this->parent, this->start, this->n);
1559}
1560
1561static int devm_region_match(struct device *dev, void *res, void *match_data)
1562{
1563 struct region_devres *this = res, *match = match_data;
1564
1565 return this->parent == match->parent &&
1566 this->start == match->start && this->n == match->n;
1567}
1568
1569struct resource *
1570__devm_request_region(struct device *dev, struct resource *parent,
1571 resource_size_t start, resource_size_t n, const char *name)
1572{
1573 struct region_devres *dr = NULL;
1574 struct resource *res;
1575
1576 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1577 GFP_KERNEL);
1578 if (!dr)
1579 return NULL;
1580
1581 dr->parent = parent;
1582 dr->start = start;
1583 dr->n = n;
1584
1585 res = __request_region(parent, start, n, name, 0);
1586 if (res)
1587 devres_add(dev, dr);
1588 else
1589 devres_free(dr);
1590
1591 return res;
1592}
1593EXPORT_SYMBOL(__devm_request_region);
1594
1595void __devm_release_region(struct device *dev, struct resource *parent,
1596 resource_size_t start, resource_size_t n)
1597{
1598 struct region_devres match_data = { parent, start, n };
1599
1600 __release_region(parent, start, n);
1601 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1602 &match_data));
1603}
1604EXPORT_SYMBOL(__devm_release_region);
1605
1606/*
1607 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1608 */
1609#define MAXRESERVE 4
1610static int __init reserve_setup(char *str)
1611{
1612 static int reserved;
1613 static struct resource reserve[MAXRESERVE];
1614
1615 for (;;) {
1616 unsigned int io_start, io_num;
1617 int x = reserved;
1618 struct resource *parent;
1619
1620 if (get_option(&str, &io_start) != 2)
1621 break;
1622 if (get_option(&str, &io_num) == 0)
1623 break;
1624 if (x < MAXRESERVE) {
1625 struct resource *res = reserve + x;
1626
1627 /*
1628 * If the region starts below 0x10000, we assume it's
1629 * I/O port space; otherwise assume it's memory.
1630 */
1631 if (io_start < 0x10000) {
1632 res->flags = IORESOURCE_IO;
1633 parent = &ioport_resource;
1634 } else {
1635 res->flags = IORESOURCE_MEM;
1636 parent = &iomem_resource;
1637 }
1638 res->name = "reserved";
1639 res->start = io_start;
1640 res->end = io_start + io_num - 1;
1641 res->flags |= IORESOURCE_BUSY;
1642 res->desc = IORES_DESC_NONE;
1643 res->child = NULL;
1644 if (request_resource(parent, res) == 0)
1645 reserved = x+1;
1646 }
1647 }
1648 return 1;
1649}
1650__setup("reserve=", reserve_setup);
1651
1652/*
1653 * Check if the requested addr and size spans more than any slot in the
1654 * iomem resource tree.
1655 */
1656int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1657{
1658 struct resource *p = &iomem_resource;
1659 resource_size_t end = addr + size - 1;
1660 int err = 0;
1661 loff_t l;
1662
1663 read_lock(&resource_lock);
1664 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1665 /*
1666 * We can probably skip the resources without
1667 * IORESOURCE_IO attribute?
1668 */
1669 if (p->start > end)
1670 continue;
1671 if (p->end < addr)
1672 continue;
1673 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1674 PFN_DOWN(p->end) >= PFN_DOWN(end))
1675 continue;
1676 /*
1677 * if a resource is "BUSY", it's not a hardware resource
1678 * but a driver mapping of such a resource; we don't want
1679 * to warn for those; some drivers legitimately map only
1680 * partial hardware resources. (example: vesafb)
1681 */
1682 if (p->flags & IORESOURCE_BUSY)
1683 continue;
1684
1685 pr_warn("resource sanity check: requesting [mem %pa-%pa], which spans more than %s %pR\n",
1686 &addr, &end, p->name, p);
1687 err = -1;
1688 break;
1689 }
1690 read_unlock(&resource_lock);
1691
1692 return err;
1693}
1694
1695#ifdef CONFIG_STRICT_DEVMEM
1696static int strict_iomem_checks = 1;
1697#else
1698static int strict_iomem_checks;
1699#endif
1700
1701/*
1702 * Check if an address is exclusive to the kernel and must not be mapped to
1703 * user space, for example, via /dev/mem.
1704 *
1705 * Returns true if exclusive to the kernel, otherwise returns false.
1706 */
1707bool resource_is_exclusive(struct resource *root, u64 addr, resource_size_t size)
1708{
1709 const unsigned int exclusive_system_ram = IORESOURCE_SYSTEM_RAM |
1710 IORESOURCE_EXCLUSIVE;
1711 bool skip_children = false, err = false;
1712 struct resource *p;
1713
1714 read_lock(&resource_lock);
1715 for_each_resource(root, p, skip_children) {
1716 if (p->start >= addr + size)
1717 break;
1718 if (p->end < addr) {
1719 skip_children = true;
1720 continue;
1721 }
1722 skip_children = false;
1723
1724 /*
1725 * IORESOURCE_SYSTEM_RAM resources are exclusive if
1726 * IORESOURCE_EXCLUSIVE is set, even if they
1727 * are not busy and even if "iomem=relaxed" is set. The
1728 * responsible driver dynamically adds/removes system RAM within
1729 * such an area and uncontrolled access is dangerous.
1730 */
1731 if ((p->flags & exclusive_system_ram) == exclusive_system_ram) {
1732 err = true;
1733 break;
1734 }
1735
1736 /*
1737 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1738 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1739 * resource is busy.
1740 */
1741 if (!strict_iomem_checks || !(p->flags & IORESOURCE_BUSY))
1742 continue;
1743 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1744 || p->flags & IORESOURCE_EXCLUSIVE) {
1745 err = true;
1746 break;
1747 }
1748 }
1749 read_unlock(&resource_lock);
1750
1751 return err;
1752}
1753
1754bool iomem_is_exclusive(u64 addr)
1755{
1756 return resource_is_exclusive(&iomem_resource, addr & PAGE_MASK,
1757 PAGE_SIZE);
1758}
1759
1760struct resource_entry *resource_list_create_entry(struct resource *res,
1761 size_t extra_size)
1762{
1763 struct resource_entry *entry;
1764
1765 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1766 if (entry) {
1767 INIT_LIST_HEAD(&entry->node);
1768 entry->res = res ? res : &entry->__res;
1769 }
1770
1771 return entry;
1772}
1773EXPORT_SYMBOL(resource_list_create_entry);
1774
1775void resource_list_free(struct list_head *head)
1776{
1777 struct resource_entry *entry, *tmp;
1778
1779 list_for_each_entry_safe(entry, tmp, head, node)
1780 resource_list_destroy_entry(entry);
1781}
1782EXPORT_SYMBOL(resource_list_free);
1783
1784#ifdef CONFIG_GET_FREE_REGION
1785#define GFR_DESCENDING (1UL << 0)
1786#define GFR_REQUEST_REGION (1UL << 1)
1787#define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT)
1788
1789static resource_size_t gfr_start(struct resource *base, resource_size_t size,
1790 resource_size_t align, unsigned long flags)
1791{
1792 if (flags & GFR_DESCENDING) {
1793 resource_size_t end;
1794
1795 end = min_t(resource_size_t, base->end,
1796 (1ULL << MAX_PHYSMEM_BITS) - 1);
1797 return end - size + 1;
1798 }
1799
1800 return ALIGN(base->start, align);
1801}
1802
1803static bool gfr_continue(struct resource *base, resource_size_t addr,
1804 resource_size_t size, unsigned long flags)
1805{
1806 if (flags & GFR_DESCENDING)
1807 return addr > size && addr >= base->start;
1808 /*
1809 * In the ascend case be careful that the last increment by
1810 * @size did not wrap 0.
1811 */
1812 return addr > addr - size &&
1813 addr <= min_t(resource_size_t, base->end,
1814 (1ULL << MAX_PHYSMEM_BITS) - 1);
1815}
1816
1817static resource_size_t gfr_next(resource_size_t addr, resource_size_t size,
1818 unsigned long flags)
1819{
1820 if (flags & GFR_DESCENDING)
1821 return addr - size;
1822 return addr + size;
1823}
1824
1825static void remove_free_mem_region(void *_res)
1826{
1827 struct resource *res = _res;
1828
1829 if (res->parent)
1830 remove_resource(res);
1831 free_resource(res);
1832}
1833
1834static struct resource *
1835get_free_mem_region(struct device *dev, struct resource *base,
1836 resource_size_t size, const unsigned long align,
1837 const char *name, const unsigned long desc,
1838 const unsigned long flags)
1839{
1840 resource_size_t addr;
1841 struct resource *res;
1842 struct region_devres *dr = NULL;
1843
1844 size = ALIGN(size, align);
1845
1846 res = alloc_resource(GFP_KERNEL);
1847 if (!res)
1848 return ERR_PTR(-ENOMEM);
1849
1850 if (dev && (flags & GFR_REQUEST_REGION)) {
1851 dr = devres_alloc(devm_region_release,
1852 sizeof(struct region_devres), GFP_KERNEL);
1853 if (!dr) {
1854 free_resource(res);
1855 return ERR_PTR(-ENOMEM);
1856 }
1857 } else if (dev) {
1858 if (devm_add_action_or_reset(dev, remove_free_mem_region, res))
1859 return ERR_PTR(-ENOMEM);
1860 }
1861
1862 write_lock(&resource_lock);
1863 for (addr = gfr_start(base, size, align, flags);
1864 gfr_continue(base, addr, size, flags);
1865 addr = gfr_next(addr, size, flags)) {
1866 if (__region_intersects(base, addr, size, 0, IORES_DESC_NONE) !=
1867 REGION_DISJOINT)
1868 continue;
1869
1870 if (flags & GFR_REQUEST_REGION) {
1871 if (__request_region_locked(res, &iomem_resource, addr,
1872 size, name, 0))
1873 break;
1874
1875 if (dev) {
1876 dr->parent = &iomem_resource;
1877 dr->start = addr;
1878 dr->n = size;
1879 devres_add(dev, dr);
1880 }
1881
1882 res->desc = desc;
1883 write_unlock(&resource_lock);
1884
1885
1886 /*
1887 * A driver is claiming this region so revoke any
1888 * mappings.
1889 */
1890 revoke_iomem(res);
1891 } else {
1892 res->start = addr;
1893 res->end = addr + size - 1;
1894 res->name = name;
1895 res->desc = desc;
1896 res->flags = IORESOURCE_MEM;
1897
1898 /*
1899 * Only succeed if the resource hosts an exclusive
1900 * range after the insert
1901 */
1902 if (__insert_resource(base, res) || res->child)
1903 break;
1904
1905 write_unlock(&resource_lock);
1906 }
1907
1908 return res;
1909 }
1910 write_unlock(&resource_lock);
1911
1912 if (flags & GFR_REQUEST_REGION) {
1913 free_resource(res);
1914 devres_free(dr);
1915 } else if (dev)
1916 devm_release_action(dev, remove_free_mem_region, res);
1917
1918 return ERR_PTR(-ERANGE);
1919}
1920
1921/**
1922 * devm_request_free_mem_region - find free region for device private memory
1923 *
1924 * @dev: device struct to bind the resource to
1925 * @size: size in bytes of the device memory to add
1926 * @base: resource tree to look in
1927 *
1928 * This function tries to find an empty range of physical address big enough to
1929 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1930 * memory, which in turn allocates struct pages.
1931 */
1932struct resource *devm_request_free_mem_region(struct device *dev,
1933 struct resource *base, unsigned long size)
1934{
1935 unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
1936
1937 return get_free_mem_region(dev, base, size, GFR_DEFAULT_ALIGN,
1938 dev_name(dev),
1939 IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
1940}
1941EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
1942
1943struct resource *request_free_mem_region(struct resource *base,
1944 unsigned long size, const char *name)
1945{
1946 unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
1947
1948 return get_free_mem_region(NULL, base, size, GFR_DEFAULT_ALIGN, name,
1949 IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
1950}
1951EXPORT_SYMBOL_GPL(request_free_mem_region);
1952
1953/**
1954 * alloc_free_mem_region - find a free region relative to @base
1955 * @base: resource that will parent the new resource
1956 * @size: size in bytes of memory to allocate from @base
1957 * @align: alignment requirements for the allocation
1958 * @name: resource name
1959 *
1960 * Buses like CXL, that can dynamically instantiate new memory regions,
1961 * need a method to allocate physical address space for those regions.
1962 * Allocate and insert a new resource to cover a free, unclaimed by a
1963 * descendant of @base, range in the span of @base.
1964 */
1965struct resource *alloc_free_mem_region(struct resource *base,
1966 unsigned long size, unsigned long align,
1967 const char *name)
1968{
1969 /* Default of ascending direction and insert resource */
1970 unsigned long flags = 0;
1971
1972 return get_free_mem_region(NULL, base, size, align, name,
1973 IORES_DESC_NONE, flags);
1974}
1975EXPORT_SYMBOL_NS_GPL(alloc_free_mem_region, CXL);
1976#endif /* CONFIG_GET_FREE_REGION */
1977
1978static int __init strict_iomem(char *str)
1979{
1980 if (strstr(str, "relaxed"))
1981 strict_iomem_checks = 0;
1982 if (strstr(str, "strict"))
1983 strict_iomem_checks = 1;
1984 return 1;
1985}
1986
1987static int iomem_fs_init_fs_context(struct fs_context *fc)
1988{
1989 return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM;
1990}
1991
1992static struct file_system_type iomem_fs_type = {
1993 .name = "iomem",
1994 .owner = THIS_MODULE,
1995 .init_fs_context = iomem_fs_init_fs_context,
1996 .kill_sb = kill_anon_super,
1997};
1998
1999static int __init iomem_init_inode(void)
2000{
2001 static struct vfsmount *iomem_vfs_mount;
2002 static int iomem_fs_cnt;
2003 struct inode *inode;
2004 int rc;
2005
2006 rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt);
2007 if (rc < 0) {
2008 pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc);
2009 return rc;
2010 }
2011
2012 inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb);
2013 if (IS_ERR(inode)) {
2014 rc = PTR_ERR(inode);
2015 pr_err("Cannot allocate inode for iomem: %d\n", rc);
2016 simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt);
2017 return rc;
2018 }
2019
2020 /*
2021 * Publish iomem revocation inode initialized.
2022 * Pairs with smp_load_acquire() in revoke_iomem().
2023 */
2024 smp_store_release(&iomem_inode, inode);
2025
2026 return 0;
2027}
2028
2029fs_initcall(iomem_init_inode);
2030
2031__setup("iomem=", strict_iomem);