projects/linux·blob v5.13-rc7 · refs

1917 lines · 48.1 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/kernel/resource.c
4 *
5 * Copyright (C) 1999 Linus Torvalds
6 * Copyright (C) 1999 Martin Mares <[email protected]>
7 *
8 * Arbitrary resource management.
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/export.h>
14#include <linux/errno.h>
15#include <linux/ioport.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18#include <linux/spinlock.h>
19#include <linux/fs.h>
20#include <linux/proc_fs.h>
21#include <linux/pseudo_fs.h>
22#include <linux/sched.h>
23#include <linux/seq_file.h>
24#include <linux/device.h>
25#include <linux/pfn.h>
26#include <linux/mm.h>
27#include <linux/mount.h>
28#include <linux/resource_ext.h>
29#include <uapi/linux/magic.h>
30#include <asm/io.h>
31
32
33struct resource ioport_resource = {
34 .name = "PCI IO",
35 .start = 0,
36 .end = IO_SPACE_LIMIT,
37 .flags = IORESOURCE_IO,
38};
39EXPORT_SYMBOL(ioport_resource);
40
41struct resource iomem_resource = {
42 .name = "PCI mem",
43 .start = 0,
44 .end = -1,
45 .flags = IORESOURCE_MEM,
46};
47EXPORT_SYMBOL(iomem_resource);
48
49/* constraints to be met while allocating resources */
50struct resource_constraint {
51 resource_size_t min, max, align;
52 resource_size_t (*alignf)(void *, const struct resource *,
53 resource_size_t, resource_size_t);
54 void *alignf_data;
55};
56
57static DEFINE_RWLOCK(resource_lock);
58
59/*
60 * For memory hotplug, there is no way to free resource entries allocated
61 * by boot mem after the system is up. So for reusing the resource entry
62 * we need to remember the resource.
63 */
64static struct resource *bootmem_resource_free;
65static DEFINE_SPINLOCK(bootmem_resource_lock);
66
67static struct resource *next_resource(struct resource *p)
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);
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 = PDE_DATA(file_inode(m->file));
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 = PDE_DATA(file_inode(m->file));
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 __init ioresources_init(void)
139{
140 proc_create_seq_data("ioports", 0, NULL, &resource_op,
141 &ioport_resource);
142 proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource);
143 return 0;
144}
145__initcall(ioresources_init);
146
147#endif /* CONFIG_PROC_FS */
148
149static void free_resource(struct resource *res)
150{
151 if (!res)
152 return;
153
154 if (!PageSlab(virt_to_head_page(res))) {
155 spin_lock(&bootmem_resource_lock);
156 res->sibling = bootmem_resource_free;
157 bootmem_resource_free = res;
158 spin_unlock(&bootmem_resource_lock);
159 } else {
160 kfree(res);
161 }
162}
163
164static struct resource *alloc_resource(gfp_t flags)
165{
166 struct resource *res = NULL;
167
168 spin_lock(&bootmem_resource_lock);
169 if (bootmem_resource_free) {
170 res = bootmem_resource_free;
171 bootmem_resource_free = res->sibling;
172 }
173 spin_unlock(&bootmem_resource_lock);
174
175 if (res)
176 memset(res, 0, sizeof(struct resource));
177 else
178 res = kzalloc(sizeof(struct resource), flags);
179
180 return res;
181}
182
183/* Return the conflict entry if you can't request it */
184static struct resource * __request_resource(struct resource *root, struct resource *new)
185{
186 resource_size_t start = new->start;
187 resource_size_t end = new->end;
188 struct resource *tmp, **p;
189
190 if (end < start)
191 return root;
192 if (start < root->start)
193 return root;
194 if (end > root->end)
195 return root;
196 p = &root->child;
197 for (;;) {
198 tmp = *p;
199 if (!tmp || tmp->start > end) {
200 new->sibling = tmp;
201 *p = new;
202 new->parent = root;
203 return NULL;
204 }
205 p = &tmp->sibling;
206 if (tmp->end < start)
207 continue;
208 return tmp;
209 }
210}
211
212static int __release_resource(struct resource *old, bool release_child)
213{
214 struct resource *tmp, **p, *chd;
215
216 p = &old->parent->child;
217 for (;;) {
218 tmp = *p;
219 if (!tmp)
220 break;
221 if (tmp == old) {
222 if (release_child || !(tmp->child)) {
223 *p = tmp->sibling;
224 } else {
225 for (chd = tmp->child;; chd = chd->sibling) {
226 chd->parent = tmp->parent;
227 if (!(chd->sibling))
228 break;
229 }
230 *p = tmp->child;
231 chd->sibling = tmp->sibling;
232 }
233 old->parent = NULL;
234 return 0;
235 }
236 p = &tmp->sibling;
237 }
238 return -EINVAL;
239}
240
241static void __release_child_resources(struct resource *r)
242{
243 struct resource *tmp, *p;
244 resource_size_t size;
245
246 p = r->child;
247 r->child = NULL;
248 while (p) {
249 tmp = p;
250 p = p->sibling;
251
252 tmp->parent = NULL;
253 tmp->sibling = NULL;
254 __release_child_resources(tmp);
255
256 printk(KERN_DEBUG "release child resource %pR\n", tmp);
257 /* need to restore size, and keep flags */
258 size = resource_size(tmp);
259 tmp->start = 0;
260 tmp->end = size - 1;
261 }
262}
263
264void release_child_resources(struct resource *r)
265{
266 write_lock(&resource_lock);
267 __release_child_resources(r);
268 write_unlock(&resource_lock);
269}
270
271/**
272 * request_resource_conflict - request and reserve an I/O or memory resource
273 * @root: root resource descriptor
274 * @new: resource descriptor desired by caller
275 *
276 * Returns 0 for success, conflict resource on error.
277 */
278struct resource *request_resource_conflict(struct resource *root, struct resource *new)
279{
280 struct resource *conflict;
281
282 write_lock(&resource_lock);
283 conflict = __request_resource(root, new);
284 write_unlock(&resource_lock);
285 return conflict;
286}
287
288/**
289 * request_resource - request and reserve an I/O or memory resource
290 * @root: root resource descriptor
291 * @new: resource descriptor desired by caller
292 *
293 * Returns 0 for success, negative error code on error.
294 */
295int request_resource(struct resource *root, struct resource *new)
296{
297 struct resource *conflict;
298
299 conflict = request_resource_conflict(root, new);
300 return conflict ? -EBUSY : 0;
301}
302
303EXPORT_SYMBOL(request_resource);
304
305/**
306 * release_resource - release a previously reserved resource
307 * @old: resource pointer
308 */
309int release_resource(struct resource *old)
310{
311 int retval;
312
313 write_lock(&resource_lock);
314 retval = __release_resource(old, true);
315 write_unlock(&resource_lock);
316 return retval;
317}
318
319EXPORT_SYMBOL(release_resource);
320
321/**
322 * find_next_iomem_res - Finds the lowest iomem resource that covers part of
323 * [@start..@end].
324 *
325 * If a resource is found, returns 0 and @*res is overwritten with the part
326 * of the resource that's within [@start..@end]; if none is found, returns
327 * -ENODEV. Returns -EINVAL for invalid parameters.
328 *
329 * @start: start address of the resource searched for
330 * @end: end address of same resource
331 * @flags: flags which the resource must have
332 * @desc: descriptor the resource must have
333 * @res: return ptr, if resource found
334 *
335 * The caller must specify @start, @end, @flags, and @desc
336 * (which may be IORES_DESC_NONE).
337 */
338static int find_next_iomem_res(resource_size_t start, resource_size_t end,
339 unsigned long flags, unsigned long desc,
340 struct resource *res)
341{
342 struct resource *p;
343
344 if (!res)
345 return -EINVAL;
346
347 if (start >= end)
348 return -EINVAL;
349
350 read_lock(&resource_lock);
351
352 for (p = iomem_resource.child; p; p = next_resource(p)) {
353 /* If we passed the resource we are looking for, stop */
354 if (p->start > end) {
355 p = NULL;
356 break;
357 }
358
359 /* Skip until we find a range that matches what we look for */
360 if (p->end < start)
361 continue;
362
363 if ((p->flags & flags) != flags)
364 continue;
365 if ((desc != IORES_DESC_NONE) && (desc != p->desc))
366 continue;
367
368 /* Found a match, break */
369 break;
370 }
371
372 if (p) {
373 /* copy data */
374 *res = (struct resource) {
375 .start = max(start, p->start),
376 .end = min(end, p->end),
377 .flags = p->flags,
378 .desc = p->desc,
379 .parent = p->parent,
380 };
381 }
382
383 read_unlock(&resource_lock);
384 return p ? 0 : -ENODEV;
385}
386
387static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
388 unsigned long flags, unsigned long desc,
389 void *arg,
390 int (*func)(struct resource *, void *))
391{
392 struct resource res;
393 int ret = -EINVAL;
394
395 while (start < end &&
396 !find_next_iomem_res(start, end, flags, desc, &res)) {
397 ret = (*func)(&res, arg);
398 if (ret)
399 break;
400
401 start = res.end + 1;
402 }
403
404 return ret;
405}
406
407/**
408 * walk_iomem_res_desc - Walks through iomem resources and calls func()
409 * with matching resource ranges.
410 * *
411 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
412 * @flags: I/O resource flags
413 * @start: start addr
414 * @end: end addr
415 * @arg: function argument for the callback @func
416 * @func: callback function that is called for each qualifying resource area
417 *
418 * All the memory ranges which overlap start,end and also match flags and
419 * desc are valid candidates.
420 *
421 * NOTE: For a new descriptor search, define a new IORES_DESC in
422 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
423 */
424int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
425 u64 end, void *arg, int (*func)(struct resource *, void *))
426{
427 return __walk_iomem_res_desc(start, end, flags, desc, arg, func);
428}
429EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
430
431/*
432 * This function calls the @func callback against all memory ranges of type
433 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
434 * Now, this function is only for System RAM, it deals with full ranges and
435 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
436 * ranges.
437 */
438int walk_system_ram_res(u64 start, u64 end, void *arg,
439 int (*func)(struct resource *, void *))
440{
441 unsigned long flags = IORESOURCE_SYSTEM_RAM | 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, which
449 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
450 */
451int walk_mem_res(u64 start, u64 end, void *arg,
452 int (*func)(struct resource *, void *))
453{
454 unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
455
456 return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
457 func);
458}
459
460/*
461 * This function calls the @func callback against all memory ranges of type
462 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
463 * It is to be used only for System RAM.
464 */
465int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
466 void *arg, int (*func)(unsigned long, unsigned long, void *))
467{
468 resource_size_t start, end;
469 unsigned long flags;
470 struct resource res;
471 unsigned long pfn, end_pfn;
472 int ret = -EINVAL;
473
474 start = (u64) start_pfn << PAGE_SHIFT;
475 end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
476 flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
477 while (start < end &&
478 !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res)) {
479 pfn = PFN_UP(res.start);
480 end_pfn = PFN_DOWN(res.end + 1);
481 if (end_pfn > pfn)
482 ret = (*func)(pfn, end_pfn - pfn, arg);
483 if (ret)
484 break;
485 start = res.end + 1;
486 }
487 return ret;
488}
489
490static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
491{
492 return 1;
493}
494
495/*
496 * This generic page_is_ram() returns true if specified address is
497 * registered as System RAM in iomem_resource list.
498 */
499int __weak page_is_ram(unsigned long pfn)
500{
501 return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
502}
503EXPORT_SYMBOL_GPL(page_is_ram);
504
505static int __region_intersects(resource_size_t start, size_t size,
506 unsigned long flags, unsigned long desc)
507{
508 struct resource res;
509 int type = 0; int other = 0;
510 struct resource *p;
511
512 res.start = start;
513 res.end = start + size - 1;
514
515 for (p = iomem_resource.child; p ; p = p->sibling) {
516 bool is_type = (((p->flags & flags) == flags) &&
517 ((desc == IORES_DESC_NONE) ||
518 (desc == p->desc)));
519
520 if (resource_overlaps(p, &res))
521 is_type ? type++ : other++;
522 }
523
524 if (type == 0)
525 return REGION_DISJOINT;
526
527 if (other == 0)
528 return REGION_INTERSECTS;
529
530 return REGION_MIXED;
531}
532
533/**
534 * region_intersects() - determine intersection of region with known resources
535 * @start: region start address
536 * @size: size of region
537 * @flags: flags of resource (in iomem_resource)
538 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
539 *
540 * Check if the specified region partially overlaps or fully eclipses a
541 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
542 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
543 * return REGION_MIXED if the region overlaps @flags/@desc and another
544 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
545 * and no other defined resource. Note that REGION_INTERSECTS is also
546 * returned in the case when the specified region overlaps RAM and undefined
547 * memory holes.
548 *
549 * region_intersect() is used by memory remapping functions to ensure
550 * the user is not remapping RAM and is a vast speed up over walking
551 * through the resource table page by page.
552 */
553int region_intersects(resource_size_t start, size_t size, unsigned long flags,
554 unsigned long desc)
555{
556 int ret;
557
558 read_lock(&resource_lock);
559 ret = __region_intersects(start, size, flags, desc);
560 read_unlock(&resource_lock);
561
562 return ret;
563}
564EXPORT_SYMBOL_GPL(region_intersects);
565
566void __weak arch_remove_reservations(struct resource *avail)
567{
568}
569
570static resource_size_t simple_align_resource(void *data,
571 const struct resource *avail,
572 resource_size_t size,
573 resource_size_t align)
574{
575 return avail->start;
576}
577
578static void resource_clip(struct resource *res, resource_size_t min,
579 resource_size_t max)
580{
581 if (res->start < min)
582 res->start = min;
583 if (res->end > max)
584 res->end = max;
585}
586
587/*
588 * Find empty slot in the resource tree with the given range and
589 * alignment constraints
590 */
591static int __find_resource(struct resource *root, struct resource *old,
592 struct resource *new,
593 resource_size_t size,
594 struct resource_constraint *constraint)
595{
596 struct resource *this = root->child;
597 struct resource tmp = *new, avail, alloc;
598
599 tmp.start = root->start;
600 /*
601 * Skip past an allocated resource that starts at 0, since the assignment
602 * of this->start - 1 to tmp->end below would cause an underflow.
603 */
604 if (this && this->start == root->start) {
605 tmp.start = (this == old) ? old->start : this->end + 1;
606 this = this->sibling;
607 }
608 for(;;) {
609 if (this)
610 tmp.end = (this == old) ? this->end : this->start - 1;
611 else
612 tmp.end = root->end;
613
614 if (tmp.end < tmp.start)
615 goto next;
616
617 resource_clip(&tmp, constraint->min, constraint->max);
618 arch_remove_reservations(&tmp);
619
620 /* Check for overflow after ALIGN() */
621 avail.start = ALIGN(tmp.start, constraint->align);
622 avail.end = tmp.end;
623 avail.flags = new->flags & ~IORESOURCE_UNSET;
624 if (avail.start >= tmp.start) {
625 alloc.flags = avail.flags;
626 alloc.start = constraint->alignf(constraint->alignf_data, &avail,
627 size, constraint->align);
628 alloc.end = alloc.start + size - 1;
629 if (alloc.start <= alloc.end &&
630 resource_contains(&avail, &alloc)) {
631 new->start = alloc.start;
632 new->end = alloc.end;
633 return 0;
634 }
635 }
636
637next: if (!this || this->end == root->end)
638 break;
639
640 if (this != old)
641 tmp.start = this->end + 1;
642 this = this->sibling;
643 }
644 return -EBUSY;
645}
646
647/*
648 * Find empty slot in the resource tree given range and alignment.
649 */
650static int find_resource(struct resource *root, struct resource *new,
651 resource_size_t size,
652 struct resource_constraint *constraint)
653{
654 return __find_resource(root, NULL, new, size, constraint);
655}
656
657/**
658 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
659 * The resource will be relocated if the new size cannot be reallocated in the
660 * current location.
661 *
662 * @root: root resource descriptor
663 * @old: resource descriptor desired by caller
664 * @newsize: new size of the resource descriptor
665 * @constraint: the size and alignment constraints to be met.
666 */
667static int reallocate_resource(struct resource *root, struct resource *old,
668 resource_size_t newsize,
669 struct resource_constraint *constraint)
670{
671 int err=0;
672 struct resource new = *old;
673 struct resource *conflict;
674
675 write_lock(&resource_lock);
676
677 if ((err = __find_resource(root, old, &new, newsize, constraint)))
678 goto out;
679
680 if (resource_contains(&new, old)) {
681 old->start = new.start;
682 old->end = new.end;
683 goto out;
684 }
685
686 if (old->child) {
687 err = -EBUSY;
688 goto out;
689 }
690
691 if (resource_contains(old, &new)) {
692 old->start = new.start;
693 old->end = new.end;
694 } else {
695 __release_resource(old, true);
696 *old = new;
697 conflict = __request_resource(root, old);
698 BUG_ON(conflict);
699 }
700out:
701 write_unlock(&resource_lock);
702 return err;
703}
704
705
706/**
707 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
708 * The resource will be reallocated with a new size if it was already allocated
709 * @root: root resource descriptor
710 * @new: resource descriptor desired by caller
711 * @size: requested resource region size
712 * @min: minimum boundary to allocate
713 * @max: maximum boundary to allocate
714 * @align: alignment requested, in bytes
715 * @alignf: alignment function, optional, called if not NULL
716 * @alignf_data: arbitrary data to pass to the @alignf function
717 */
718int allocate_resource(struct resource *root, struct resource *new,
719 resource_size_t size, resource_size_t min,
720 resource_size_t max, resource_size_t align,
721 resource_size_t (*alignf)(void *,
722 const struct resource *,
723 resource_size_t,
724 resource_size_t),
725 void *alignf_data)
726{
727 int err;
728 struct resource_constraint constraint;
729
730 if (!alignf)
731 alignf = simple_align_resource;
732
733 constraint.min = min;
734 constraint.max = max;
735 constraint.align = align;
736 constraint.alignf = alignf;
737 constraint.alignf_data = alignf_data;
738
739 if ( new->parent ) {
740 /* resource is already allocated, try reallocating with
741 the new constraints */
742 return reallocate_resource(root, new, size, &constraint);
743 }
744
745 write_lock(&resource_lock);
746 err = find_resource(root, new, size, &constraint);
747 if (err >= 0 && __request_resource(root, new))
748 err = -EBUSY;
749 write_unlock(&resource_lock);
750 return err;
751}
752
753EXPORT_SYMBOL(allocate_resource);
754
755/**
756 * lookup_resource - find an existing resource by a resource start address
757 * @root: root resource descriptor
758 * @start: resource start address
759 *
760 * Returns a pointer to the resource if found, NULL otherwise
761 */
762struct resource *lookup_resource(struct resource *root, resource_size_t start)
763{
764 struct resource *res;
765
766 read_lock(&resource_lock);
767 for (res = root->child; res; res = res->sibling) {
768 if (res->start == start)
769 break;
770 }
771 read_unlock(&resource_lock);
772
773 return res;
774}
775
776/*
777 * Insert a resource into the resource tree. If successful, return NULL,
778 * otherwise return the conflicting resource (compare to __request_resource())
779 */
780static struct resource * __insert_resource(struct resource *parent, struct resource *new)
781{
782 struct resource *first, *next;
783
784 for (;; parent = first) {
785 first = __request_resource(parent, new);
786 if (!first)
787 return first;
788
789 if (first == parent)
790 return first;
791 if (WARN_ON(first == new)) /* duplicated insertion */
792 return first;
793
794 if ((first->start > new->start) || (first->end < new->end))
795 break;
796 if ((first->start == new->start) && (first->end == new->end))
797 break;
798 }
799
800 for (next = first; ; next = next->sibling) {
801 /* Partial overlap? Bad, and unfixable */
802 if (next->start < new->start || next->end > new->end)
803 return next;
804 if (!next->sibling)
805 break;
806 if (next->sibling->start > new->end)
807 break;
808 }
809
810 new->parent = parent;
811 new->sibling = next->sibling;
812 new->child = first;
813
814 next->sibling = NULL;
815 for (next = first; next; next = next->sibling)
816 next->parent = new;
817
818 if (parent->child == first) {
819 parent->child = new;
820 } else {
821 next = parent->child;
822 while (next->sibling != first)
823 next = next->sibling;
824 next->sibling = new;
825 }
826 return NULL;
827}
828
829/**
830 * insert_resource_conflict - Inserts resource in the resource tree
831 * @parent: parent of the new resource
832 * @new: new resource to insert
833 *
834 * Returns 0 on success, conflict resource if the resource can't be inserted.
835 *
836 * This function is equivalent to request_resource_conflict when no conflict
837 * happens. If a conflict happens, and the conflicting resources
838 * entirely fit within the range of the new resource, then the new
839 * resource is inserted and the conflicting resources become children of
840 * the new resource.
841 *
842 * This function is intended for producers of resources, such as FW modules
843 * and bus drivers.
844 */
845struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
846{
847 struct resource *conflict;
848
849 write_lock(&resource_lock);
850 conflict = __insert_resource(parent, new);
851 write_unlock(&resource_lock);
852 return conflict;
853}
854
855/**
856 * insert_resource - Inserts a resource in the resource tree
857 * @parent: parent of the new resource
858 * @new: new resource to insert
859 *
860 * Returns 0 on success, -EBUSY if the resource can't be inserted.
861 *
862 * This function is intended for producers of resources, such as FW modules
863 * and bus drivers.
864 */
865int insert_resource(struct resource *parent, struct resource *new)
866{
867 struct resource *conflict;
868
869 conflict = insert_resource_conflict(parent, new);
870 return conflict ? -EBUSY : 0;
871}
872EXPORT_SYMBOL_GPL(insert_resource);
873
874/**
875 * insert_resource_expand_to_fit - Insert a resource into the resource tree
876 * @root: root resource descriptor
877 * @new: new resource to insert
878 *
879 * Insert a resource into the resource tree, possibly expanding it in order
880 * to make it encompass any conflicting resources.
881 */
882void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
883{
884 if (new->parent)
885 return;
886
887 write_lock(&resource_lock);
888 for (;;) {
889 struct resource *conflict;
890
891 conflict = __insert_resource(root, new);
892 if (!conflict)
893 break;
894 if (conflict == root)
895 break;
896
897 /* Ok, expand resource to cover the conflict, then try again .. */
898 if (conflict->start < new->start)
899 new->start = conflict->start;
900 if (conflict->end > new->end)
901 new->end = conflict->end;
902
903 printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
904 }
905 write_unlock(&resource_lock);
906}
907
908/**
909 * remove_resource - Remove a resource in the resource tree
910 * @old: resource to remove
911 *
912 * Returns 0 on success, -EINVAL if the resource is not valid.
913 *
914 * This function removes a resource previously inserted by insert_resource()
915 * or insert_resource_conflict(), and moves the children (if any) up to
916 * where they were before. insert_resource() and insert_resource_conflict()
917 * insert a new resource, and move any conflicting resources down to the
918 * children of the new resource.
919 *
920 * insert_resource(), insert_resource_conflict() and remove_resource() are
921 * intended for producers of resources, such as FW modules and bus drivers.
922 */
923int remove_resource(struct resource *old)
924{
925 int retval;
926
927 write_lock(&resource_lock);
928 retval = __release_resource(old, false);
929 write_unlock(&resource_lock);
930 return retval;
931}
932EXPORT_SYMBOL_GPL(remove_resource);
933
934static int __adjust_resource(struct resource *res, resource_size_t start,
935 resource_size_t size)
936{
937 struct resource *tmp, *parent = res->parent;
938 resource_size_t end = start + size - 1;
939 int result = -EBUSY;
940
941 if (!parent)
942 goto skip;
943
944 if ((start < parent->start) || (end > parent->end))
945 goto out;
946
947 if (res->sibling && (res->sibling->start <= end))
948 goto out;
949
950 tmp = parent->child;
951 if (tmp != res) {
952 while (tmp->sibling != res)
953 tmp = tmp->sibling;
954 if (start <= tmp->end)
955 goto out;
956 }
957
958skip:
959 for (tmp = res->child; tmp; tmp = tmp->sibling)
960 if ((tmp->start < start) || (tmp->end > end))
961 goto out;
962
963 res->start = start;
964 res->end = end;
965 result = 0;
966
967 out:
968 return result;
969}
970
971/**
972 * adjust_resource - modify a resource's start and size
973 * @res: resource to modify
974 * @start: new start value
975 * @size: new size
976 *
977 * Given an existing resource, change its start and size to match the
978 * arguments. Returns 0 on success, -EBUSY if it can't fit.
979 * Existing children of the resource are assumed to be immutable.
980 */
981int adjust_resource(struct resource *res, resource_size_t start,
982 resource_size_t size)
983{
984 int result;
985
986 write_lock(&resource_lock);
987 result = __adjust_resource(res, start, size);
988 write_unlock(&resource_lock);
989 return result;
990}
991EXPORT_SYMBOL(adjust_resource);
992
993static void __init
994__reserve_region_with_split(struct resource *root, resource_size_t start,
995 resource_size_t end, const char *name)
996{
997 struct resource *parent = root;
998 struct resource *conflict;
999 struct resource *res = alloc_resource(GFP_ATOMIC);
1000 struct resource *next_res = NULL;
1001 int type = resource_type(root);
1002
1003 if (!res)
1004 return;
1005
1006 res->name = name;
1007 res->start = start;
1008 res->end = end;
1009 res->flags = type | IORESOURCE_BUSY;
1010 res->desc = IORES_DESC_NONE;
1011
1012 while (1) {
1013
1014 conflict = __request_resource(parent, res);
1015 if (!conflict) {
1016 if (!next_res)
1017 break;
1018 res = next_res;
1019 next_res = NULL;
1020 continue;
1021 }
1022
1023 /* conflict covered whole area */
1024 if (conflict->start <= res->start &&
1025 conflict->end >= res->end) {
1026 free_resource(res);
1027 WARN_ON(next_res);
1028 break;
1029 }
1030
1031 /* failed, split and try again */
1032 if (conflict->start > res->start) {
1033 end = res->end;
1034 res->end = conflict->start - 1;
1035 if (conflict->end < end) {
1036 next_res = alloc_resource(GFP_ATOMIC);
1037 if (!next_res) {
1038 free_resource(res);
1039 break;
1040 }
1041 next_res->name = name;
1042 next_res->start = conflict->end + 1;
1043 next_res->end = end;
1044 next_res->flags = type | IORESOURCE_BUSY;
1045 next_res->desc = IORES_DESC_NONE;
1046 }
1047 } else {
1048 res->start = conflict->end + 1;
1049 }
1050 }
1051
1052}
1053
1054void __init
1055reserve_region_with_split(struct resource *root, resource_size_t start,
1056 resource_size_t end, const char *name)
1057{
1058 int abort = 0;
1059
1060 write_lock(&resource_lock);
1061 if (root->start > start || root->end < end) {
1062 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1063 (unsigned long long)start, (unsigned long long)end,
1064 root);
1065 if (start > root->end || end < root->start)
1066 abort = 1;
1067 else {
1068 if (end > root->end)
1069 end = root->end;
1070 if (start < root->start)
1071 start = root->start;
1072 pr_err("fixing request to [0x%llx-0x%llx]\n",
1073 (unsigned long long)start,
1074 (unsigned long long)end);
1075 }
1076 dump_stack();
1077 }
1078 if (!abort)
1079 __reserve_region_with_split(root, start, end, name);
1080 write_unlock(&resource_lock);
1081}
1082
1083/**
1084 * resource_alignment - calculate resource's alignment
1085 * @res: resource pointer
1086 *
1087 * Returns alignment on success, 0 (invalid alignment) on failure.
1088 */
1089resource_size_t resource_alignment(struct resource *res)
1090{
1091 switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1092 case IORESOURCE_SIZEALIGN:
1093 return resource_size(res);
1094 case IORESOURCE_STARTALIGN:
1095 return res->start;
1096 default:
1097 return 0;
1098 }
1099}
1100
1101/*
1102 * This is compatibility stuff for IO resources.
1103 *
1104 * Note how this, unlike the above, knows about
1105 * the IO flag meanings (busy etc).
1106 *
1107 * request_region creates a new busy region.
1108 *
1109 * release_region releases a matching busy region.
1110 */
1111
1112static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1113
1114static struct inode *iomem_inode;
1115
1116#ifdef CONFIG_IO_STRICT_DEVMEM
1117static void revoke_iomem(struct resource *res)
1118{
1119 /* pairs with smp_store_release() in iomem_init_inode() */
1120 struct inode *inode = smp_load_acquire(&iomem_inode);
1121
1122 /*
1123 * Check that the initialization has completed. Losing the race
1124 * is ok because it means drivers are claiming resources before
1125 * the fs_initcall level of init and prevent iomem_get_mapping users
1126 * from establishing mappings.
1127 */
1128 if (!inode)
1129 return;
1130
1131 /*
1132 * The expectation is that the driver has successfully marked
1133 * the resource busy by this point, so devmem_is_allowed()
1134 * should start returning false, however for performance this
1135 * does not iterate the entire resource range.
1136 */
1137 if (devmem_is_allowed(PHYS_PFN(res->start)) &&
1138 devmem_is_allowed(PHYS_PFN(res->end))) {
1139 /*
1140 * *cringe* iomem=relaxed says "go ahead, what's the
1141 * worst that can happen?"
1142 */
1143 return;
1144 }
1145
1146 unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1);
1147}
1148#else
1149static void revoke_iomem(struct resource *res) {}
1150#endif
1151
1152struct address_space *iomem_get_mapping(void)
1153{
1154 /*
1155 * This function is only called from file open paths, hence guaranteed
1156 * that fs_initcalls have completed and no need to check for NULL. But
1157 * since revoke_iomem can be called before the initcall we still need
1158 * the barrier to appease checkers.
1159 */
1160 return smp_load_acquire(&iomem_inode)->i_mapping;
1161}
1162
1163static int __request_region_locked(struct resource *res, struct resource *parent,
1164 resource_size_t start, resource_size_t n,
1165 const char *name, int flags)
1166{
1167 DECLARE_WAITQUEUE(wait, current);
1168
1169 res->name = name;
1170 res->start = start;
1171 res->end = start + n - 1;
1172
1173 for (;;) {
1174 struct resource *conflict;
1175
1176 res->flags = resource_type(parent) | resource_ext_type(parent);
1177 res->flags |= IORESOURCE_BUSY | flags;
1178 res->desc = parent->desc;
1179
1180 conflict = __request_resource(parent, res);
1181 if (!conflict)
1182 break;
1183 /*
1184 * mm/hmm.c reserves physical addresses which then
1185 * become unavailable to other users. Conflicts are
1186 * not expected. Warn to aid debugging if encountered.
1187 */
1188 if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1189 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1190 conflict->name, conflict, res);
1191 }
1192 if (conflict != parent) {
1193 if (!(conflict->flags & IORESOURCE_BUSY)) {
1194 parent = conflict;
1195 continue;
1196 }
1197 }
1198 if (conflict->flags & flags & IORESOURCE_MUXED) {
1199 add_wait_queue(&muxed_resource_wait, &wait);
1200 write_unlock(&resource_lock);
1201 set_current_state(TASK_UNINTERRUPTIBLE);
1202 schedule();
1203 remove_wait_queue(&muxed_resource_wait, &wait);
1204 write_lock(&resource_lock);
1205 continue;
1206 }
1207 /* Uhhuh, that didn't work out.. */
1208 return -EBUSY;
1209 }
1210
1211 return 0;
1212}
1213
1214/**
1215 * __request_region - create a new busy resource region
1216 * @parent: parent resource descriptor
1217 * @start: resource start address
1218 * @n: resource region size
1219 * @name: reserving caller's ID string
1220 * @flags: IO resource flags
1221 */
1222struct resource *__request_region(struct resource *parent,
1223 resource_size_t start, resource_size_t n,
1224 const char *name, int flags)
1225{
1226 struct resource *res = alloc_resource(GFP_KERNEL);
1227 int ret;
1228
1229 if (!res)
1230 return NULL;
1231
1232 write_lock(&resource_lock);
1233 ret = __request_region_locked(res, parent, start, n, name, flags);
1234 write_unlock(&resource_lock);
1235
1236 if (ret) {
1237 free_resource(res);
1238 return NULL;
1239 }
1240
1241 if (parent == &iomem_resource)
1242 revoke_iomem(res);
1243
1244 return res;
1245}
1246EXPORT_SYMBOL(__request_region);
1247
1248/**
1249 * __release_region - release a previously reserved resource region
1250 * @parent: parent resource descriptor
1251 * @start: resource start address
1252 * @n: resource region size
1253 *
1254 * The described resource region must match a currently busy region.
1255 */
1256void __release_region(struct resource *parent, resource_size_t start,
1257 resource_size_t n)
1258{
1259 struct resource **p;
1260 resource_size_t end;
1261
1262 p = &parent->child;
1263 end = start + n - 1;
1264
1265 write_lock(&resource_lock);
1266
1267 for (;;) {
1268 struct resource *res = *p;
1269
1270 if (!res)
1271 break;
1272 if (res->start <= start && res->end >= end) {
1273 if (!(res->flags & IORESOURCE_BUSY)) {
1274 p = &res->child;
1275 continue;
1276 }
1277 if (res->start != start || res->end != end)
1278 break;
1279 *p = res->sibling;
1280 write_unlock(&resource_lock);
1281 if (res->flags & IORESOURCE_MUXED)
1282 wake_up(&muxed_resource_wait);
1283 free_resource(res);
1284 return;
1285 }
1286 p = &res->sibling;
1287 }
1288
1289 write_unlock(&resource_lock);
1290
1291 printk(KERN_WARNING "Trying to free nonexistent resource "
1292 "<%016llx-%016llx>\n", (unsigned long long)start,
1293 (unsigned long long)end);
1294}
1295EXPORT_SYMBOL(__release_region);
1296
1297#ifdef CONFIG_MEMORY_HOTREMOVE
1298/**
1299 * release_mem_region_adjustable - release a previously reserved memory region
1300 * @start: resource start address
1301 * @size: resource region size
1302 *
1303 * This interface is intended for memory hot-delete. The requested region
1304 * is released from a currently busy memory resource. The requested region
1305 * must either match exactly or fit into a single busy resource entry. In
1306 * the latter case, the remaining resource is adjusted accordingly.
1307 * Existing children of the busy memory resource must be immutable in the
1308 * request.
1309 *
1310 * Note:
1311 * - Additional release conditions, such as overlapping region, can be
1312 * supported after they are confirmed as valid cases.
1313 * - When a busy memory resource gets split into two entries, the code
1314 * assumes that all children remain in the lower address entry for
1315 * simplicity. Enhance this logic when necessary.
1316 */
1317void release_mem_region_adjustable(resource_size_t start, resource_size_t size)
1318{
1319 struct resource *parent = &iomem_resource;
1320 struct resource *new_res = NULL;
1321 bool alloc_nofail = false;
1322 struct resource **p;
1323 struct resource *res;
1324 resource_size_t end;
1325
1326 end = start + size - 1;
1327 if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
1328 return;
1329
1330 /*
1331 * We free up quite a lot of memory on memory hotunplug (esp., memap),
1332 * just before releasing the region. This is highly unlikely to
1333 * fail - let's play save and make it never fail as the caller cannot
1334 * perform any error handling (e.g., trying to re-add memory will fail
1335 * similarly).
1336 */
1337retry:
1338 new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
1339
1340 p = &parent->child;
1341 write_lock(&resource_lock);
1342
1343 while ((res = *p)) {
1344 if (res->start >= end)
1345 break;
1346
1347 /* look for the next resource if it does not fit into */
1348 if (res->start > start || res->end < end) {
1349 p = &res->sibling;
1350 continue;
1351 }
1352
1353 /*
1354 * All memory regions added from memory-hotplug path have the
1355 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1356 * this flag, we know that we are dealing with a resource coming
1357 * from HMM/devm. HMM/devm use another mechanism to add/release
1358 * a resource. This goes via devm_request_mem_region and
1359 * devm_release_mem_region.
1360 * HMM/devm take care to release their resources when they want,
1361 * so if we are dealing with them, let us just back off here.
1362 */
1363 if (!(res->flags & IORESOURCE_SYSRAM)) {
1364 break;
1365 }
1366
1367 if (!(res->flags & IORESOURCE_MEM))
1368 break;
1369
1370 if (!(res->flags & IORESOURCE_BUSY)) {
1371 p = &res->child;
1372 continue;
1373 }
1374
1375 /* found the target resource; let's adjust accordingly */
1376 if (res->start == start && res->end == end) {
1377 /* free the whole entry */
1378 *p = res->sibling;
1379 free_resource(res);
1380 } else if (res->start == start && res->end != end) {
1381 /* adjust the start */
1382 WARN_ON_ONCE(__adjust_resource(res, end + 1,
1383 res->end - end));
1384 } else if (res->start != start && res->end == end) {
1385 /* adjust the end */
1386 WARN_ON_ONCE(__adjust_resource(res, res->start,
1387 start - res->start));
1388 } else {
1389 /* split into two entries - we need a new resource */
1390 if (!new_res) {
1391 new_res = alloc_resource(GFP_ATOMIC);
1392 if (!new_res) {
1393 alloc_nofail = true;
1394 write_unlock(&resource_lock);
1395 goto retry;
1396 }
1397 }
1398 new_res->name = res->name;
1399 new_res->start = end + 1;
1400 new_res->end = res->end;
1401 new_res->flags = res->flags;
1402 new_res->desc = res->desc;
1403 new_res->parent = res->parent;
1404 new_res->sibling = res->sibling;
1405 new_res->child = NULL;
1406
1407 if (WARN_ON_ONCE(__adjust_resource(res, res->start,
1408 start - res->start)))
1409 break;
1410 res->sibling = new_res;
1411 new_res = NULL;
1412 }
1413
1414 break;
1415 }
1416
1417 write_unlock(&resource_lock);
1418 free_resource(new_res);
1419}
1420#endif /* CONFIG_MEMORY_HOTREMOVE */
1421
1422#ifdef CONFIG_MEMORY_HOTPLUG
1423static bool system_ram_resources_mergeable(struct resource *r1,
1424 struct resource *r2)
1425{
1426 /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1427 return r1->flags == r2->flags && r1->end + 1 == r2->start &&
1428 r1->name == r2->name && r1->desc == r2->desc &&
1429 !r1->child && !r2->child;
1430}
1431
1432/**
1433 * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1434 * merge it with adjacent, mergeable resources
1435 * @res: resource descriptor
1436 *
1437 * This interface is intended for memory hotplug, whereby lots of contiguous
1438 * system ram resources are added (e.g., via add_memory*()) by a driver, and
1439 * the actual resource boundaries are not of interest (e.g., it might be
1440 * relevant for DIMMs). Only resources that are marked mergeable, that have the
1441 * same parent, and that don't have any children are considered. All mergeable
1442 * resources must be immutable during the request.
1443 *
1444 * Note:
1445 * - The caller has to make sure that no pointers to resources that are
1446 * marked mergeable are used anymore after this call - the resource might
1447 * be freed and the pointer might be stale!
1448 * - release_mem_region_adjustable() will split on demand on memory hotunplug
1449 */
1450void merge_system_ram_resource(struct resource *res)
1451{
1452 const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
1453 struct resource *cur;
1454
1455 if (WARN_ON_ONCE((res->flags & flags) != flags))
1456 return;
1457
1458 write_lock(&resource_lock);
1459 res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
1460
1461 /* Try to merge with next item in the list. */
1462 cur = res->sibling;
1463 if (cur && system_ram_resources_mergeable(res, cur)) {
1464 res->end = cur->end;
1465 res->sibling = cur->sibling;
1466 free_resource(cur);
1467 }
1468
1469 /* Try to merge with previous item in the list. */
1470 cur = res->parent->child;
1471 while (cur && cur->sibling != res)
1472 cur = cur->sibling;
1473 if (cur && system_ram_resources_mergeable(cur, res)) {
1474 cur->end = res->end;
1475 cur->sibling = res->sibling;
1476 free_resource(res);
1477 }
1478 write_unlock(&resource_lock);
1479}
1480#endif /* CONFIG_MEMORY_HOTPLUG */
1481
1482/*
1483 * Managed region resource
1484 */
1485static void devm_resource_release(struct device *dev, void *ptr)
1486{
1487 struct resource **r = ptr;
1488
1489 release_resource(*r);
1490}
1491
1492/**
1493 * devm_request_resource() - request and reserve an I/O or memory resource
1494 * @dev: device for which to request the resource
1495 * @root: root of the resource tree from which to request the resource
1496 * @new: descriptor of the resource to request
1497 *
1498 * This is a device-managed version of request_resource(). There is usually
1499 * no need to release resources requested by this function explicitly since
1500 * that will be taken care of when the device is unbound from its driver.
1501 * If for some reason the resource needs to be released explicitly, because
1502 * of ordering issues for example, drivers must call devm_release_resource()
1503 * rather than the regular release_resource().
1504 *
1505 * When a conflict is detected between any existing resources and the newly
1506 * requested resource, an error message will be printed.
1507 *
1508 * Returns 0 on success or a negative error code on failure.
1509 */
1510int devm_request_resource(struct device *dev, struct resource *root,
1511 struct resource *new)
1512{
1513 struct resource *conflict, **ptr;
1514
1515 ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1516 if (!ptr)
1517 return -ENOMEM;
1518
1519 *ptr = new;
1520
1521 conflict = request_resource_conflict(root, new);
1522 if (conflict) {
1523 dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1524 new, conflict->name, conflict);
1525 devres_free(ptr);
1526 return -EBUSY;
1527 }
1528
1529 devres_add(dev, ptr);
1530 return 0;
1531}
1532EXPORT_SYMBOL(devm_request_resource);
1533
1534static int devm_resource_match(struct device *dev, void *res, void *data)
1535{
1536 struct resource **ptr = res;
1537
1538 return *ptr == data;
1539}
1540
1541/**
1542 * devm_release_resource() - release a previously requested resource
1543 * @dev: device for which to release the resource
1544 * @new: descriptor of the resource to release
1545 *
1546 * Releases a resource previously requested using devm_request_resource().
1547 */
1548void devm_release_resource(struct device *dev, struct resource *new)
1549{
1550 WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1551 new));
1552}
1553EXPORT_SYMBOL(devm_release_resource);
1554
1555struct region_devres {
1556 struct resource *parent;
1557 resource_size_t start;
1558 resource_size_t n;
1559};
1560
1561static void devm_region_release(struct device *dev, void *res)
1562{
1563 struct region_devres *this = res;
1564
1565 __release_region(this->parent, this->start, this->n);
1566}
1567
1568static int devm_region_match(struct device *dev, void *res, void *match_data)
1569{
1570 struct region_devres *this = res, *match = match_data;
1571
1572 return this->parent == match->parent &&
1573 this->start == match->start && this->n == match->n;
1574}
1575
1576struct resource *
1577__devm_request_region(struct device *dev, struct resource *parent,
1578 resource_size_t start, resource_size_t n, const char *name)
1579{
1580 struct region_devres *dr = NULL;
1581 struct resource *res;
1582
1583 dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1584 GFP_KERNEL);
1585 if (!dr)
1586 return NULL;
1587
1588 dr->parent = parent;
1589 dr->start = start;
1590 dr->n = n;
1591
1592 res = __request_region(parent, start, n, name, 0);
1593 if (res)
1594 devres_add(dev, dr);
1595 else
1596 devres_free(dr);
1597
1598 return res;
1599}
1600EXPORT_SYMBOL(__devm_request_region);
1601
1602void __devm_release_region(struct device *dev, struct resource *parent,
1603 resource_size_t start, resource_size_t n)
1604{
1605 struct region_devres match_data = { parent, start, n };
1606
1607 __release_region(parent, start, n);
1608 WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1609 &match_data));
1610}
1611EXPORT_SYMBOL(__devm_release_region);
1612
1613/*
1614 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1615 */
1616#define MAXRESERVE 4
1617static int __init reserve_setup(char *str)
1618{
1619 static int reserved;
1620 static struct resource reserve[MAXRESERVE];
1621
1622 for (;;) {
1623 unsigned int io_start, io_num;
1624 int x = reserved;
1625 struct resource *parent;
1626
1627 if (get_option(&str, &io_start) != 2)
1628 break;
1629 if (get_option(&str, &io_num) == 0)
1630 break;
1631 if (x < MAXRESERVE) {
1632 struct resource *res = reserve + x;
1633
1634 /*
1635 * If the region starts below 0x10000, we assume it's
1636 * I/O port space; otherwise assume it's memory.
1637 */
1638 if (io_start < 0x10000) {
1639 res->flags = IORESOURCE_IO;
1640 parent = &ioport_resource;
1641 } else {
1642 res->flags = IORESOURCE_MEM;
1643 parent = &iomem_resource;
1644 }
1645 res->name = "reserved";
1646 res->start = io_start;
1647 res->end = io_start + io_num - 1;
1648 res->flags |= IORESOURCE_BUSY;
1649 res->desc = IORES_DESC_NONE;
1650 res->child = NULL;
1651 if (request_resource(parent, res) == 0)
1652 reserved = x+1;
1653 }
1654 }
1655 return 1;
1656}
1657__setup("reserve=", reserve_setup);
1658
1659/*
1660 * Check if the requested addr and size spans more than any slot in the
1661 * iomem resource tree.
1662 */
1663int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1664{
1665 struct resource *p = &iomem_resource;
1666 int err = 0;
1667 loff_t l;
1668
1669 read_lock(&resource_lock);
1670 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1671 /*
1672 * We can probably skip the resources without
1673 * IORESOURCE_IO attribute?
1674 */
1675 if (p->start >= addr + size)
1676 continue;
1677 if (p->end < addr)
1678 continue;
1679 if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1680 PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1681 continue;
1682 /*
1683 * if a resource is "BUSY", it's not a hardware resource
1684 * but a driver mapping of such a resource; we don't want
1685 * to warn for those; some drivers legitimately map only
1686 * partial hardware resources. (example: vesafb)
1687 */
1688 if (p->flags & IORESOURCE_BUSY)
1689 continue;
1690
1691 printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1692 (unsigned long long)addr,
1693 (unsigned long long)(addr + size - 1),
1694 p->name, p);
1695 err = -1;
1696 break;
1697 }
1698 read_unlock(&resource_lock);
1699
1700 return err;
1701}
1702
1703#ifdef CONFIG_STRICT_DEVMEM
1704static int strict_iomem_checks = 1;
1705#else
1706static int strict_iomem_checks;
1707#endif
1708
1709/*
1710 * check if an address is reserved in the iomem resource tree
1711 * returns true if reserved, false if not reserved.
1712 */
1713bool iomem_is_exclusive(u64 addr)
1714{
1715 struct resource *p = &iomem_resource;
1716 bool err = false;
1717 loff_t l;
1718 int size = PAGE_SIZE;
1719
1720 if (!strict_iomem_checks)
1721 return false;
1722
1723 addr = addr & PAGE_MASK;
1724
1725 read_lock(&resource_lock);
1726 for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1727 /*
1728 * We can probably skip the resources without
1729 * IORESOURCE_IO attribute?
1730 */
1731 if (p->start >= addr + size)
1732 break;
1733 if (p->end < addr)
1734 continue;
1735 /*
1736 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1737 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1738 * resource is busy.
1739 */
1740 if ((p->flags & IORESOURCE_BUSY) == 0)
1741 continue;
1742 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1743 || p->flags & IORESOURCE_EXCLUSIVE) {
1744 err = true;
1745 break;
1746 }
1747 }
1748 read_unlock(&resource_lock);
1749
1750 return err;
1751}
1752
1753struct resource_entry *resource_list_create_entry(struct resource *res,
1754 size_t extra_size)
1755{
1756 struct resource_entry *entry;
1757
1758 entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1759 if (entry) {
1760 INIT_LIST_HEAD(&entry->node);
1761 entry->res = res ? res : &entry->__res;
1762 }
1763
1764 return entry;
1765}
1766EXPORT_SYMBOL(resource_list_create_entry);
1767
1768void resource_list_free(struct list_head *head)
1769{
1770 struct resource_entry *entry, *tmp;
1771
1772 list_for_each_entry_safe(entry, tmp, head, node)
1773 resource_list_destroy_entry(entry);
1774}
1775EXPORT_SYMBOL(resource_list_free);
1776
1777#ifdef CONFIG_DEVICE_PRIVATE
1778static struct resource *__request_free_mem_region(struct device *dev,
1779 struct resource *base, unsigned long size, const char *name)
1780{
1781 resource_size_t end, addr;
1782 struct resource *res;
1783 struct region_devres *dr = NULL;
1784
1785 size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
1786 end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
1787 addr = end - size + 1UL;
1788
1789 res = alloc_resource(GFP_KERNEL);
1790 if (!res)
1791 return ERR_PTR(-ENOMEM);
1792
1793 if (dev) {
1794 dr = devres_alloc(devm_region_release,
1795 sizeof(struct region_devres), GFP_KERNEL);
1796 if (!dr) {
1797 free_resource(res);
1798 return ERR_PTR(-ENOMEM);
1799 }
1800 }
1801
1802 write_lock(&resource_lock);
1803 for (; addr > size && addr >= base->start; addr -= size) {
1804 if (__region_intersects(addr, size, 0, IORES_DESC_NONE) !=
1805 REGION_DISJOINT)
1806 continue;
1807
1808 if (__request_region_locked(res, &iomem_resource, addr, size,
1809 name, 0))
1810 break;
1811
1812 if (dev) {
1813 dr->parent = &iomem_resource;
1814 dr->start = addr;
1815 dr->n = size;
1816 devres_add(dev, dr);
1817 }
1818
1819 res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
1820 write_unlock(&resource_lock);
1821
1822 /*
1823 * A driver is claiming this region so revoke any mappings.
1824 */
1825 revoke_iomem(res);
1826 return res;
1827 }
1828 write_unlock(&resource_lock);
1829
1830 free_resource(res);
1831 if (dr)
1832 devres_free(dr);
1833
1834 return ERR_PTR(-ERANGE);
1835}
1836
1837/**
1838 * devm_request_free_mem_region - find free region for device private memory
1839 *
1840 * @dev: device struct to bind the resource to
1841 * @size: size in bytes of the device memory to add
1842 * @base: resource tree to look in
1843 *
1844 * This function tries to find an empty range of physical address big enough to
1845 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1846 * memory, which in turn allocates struct pages.
1847 */
1848struct resource *devm_request_free_mem_region(struct device *dev,
1849 struct resource *base, unsigned long size)
1850{
1851 return __request_free_mem_region(dev, base, size, dev_name(dev));
1852}
1853EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
1854
1855struct resource *request_free_mem_region(struct resource *base,
1856 unsigned long size, const char *name)
1857{
1858 return __request_free_mem_region(NULL, base, size, name);
1859}
1860EXPORT_SYMBOL_GPL(request_free_mem_region);
1861
1862#endif /* CONFIG_DEVICE_PRIVATE */
1863
1864static int __init strict_iomem(char *str)
1865{
1866 if (strstr(str, "relaxed"))
1867 strict_iomem_checks = 0;
1868 if (strstr(str, "strict"))
1869 strict_iomem_checks = 1;
1870 return 1;
1871}
1872
1873static int iomem_fs_init_fs_context(struct fs_context *fc)
1874{
1875 return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM;
1876}
1877
1878static struct file_system_type iomem_fs_type = {
1879 .name = "iomem",
1880 .owner = THIS_MODULE,
1881 .init_fs_context = iomem_fs_init_fs_context,
1882 .kill_sb = kill_anon_super,
1883};
1884
1885static int __init iomem_init_inode(void)
1886{
1887 static struct vfsmount *iomem_vfs_mount;
1888 static int iomem_fs_cnt;
1889 struct inode *inode;
1890 int rc;
1891
1892 rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt);
1893 if (rc < 0) {
1894 pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc);
1895 return rc;
1896 }
1897
1898 inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb);
1899 if (IS_ERR(inode)) {
1900 rc = PTR_ERR(inode);
1901 pr_err("Cannot allocate inode for iomem: %d\n", rc);
1902 simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt);
1903 return rc;
1904 }
1905
1906 /*
1907 * Publish iomem revocation inode initialized.
1908 * Pairs with smp_load_acquire() in revoke_iomem().
1909 */
1910 smp_store_release(&iomem_inode, inode);
1911
1912 return 0;
1913}
1914
1915fs_initcall(iomem_init_inode);
1916
1917__setup("iomem=", strict_iomem);