1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/kernel/resource.c
5 * Copyright (C) 1999 Linus Torvalds
6 * Copyright (C) 1999 Martin Mares <mj@ucw.cz>
8 * Arbitrary resource management.
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
20 #include <linux/proc_fs.h>
21 #include <linux/sched.h>
22 #include <linux/seq_file.h>
23 #include <linux/device.h>
24 #include <linux/pfn.h>
26 #include <linux/resource_ext.h>
30 struct resource ioport_resource
= {
33 .end
= IO_SPACE_LIMIT
,
34 .flags
= IORESOURCE_IO
,
36 EXPORT_SYMBOL(ioport_resource
);
38 struct resource iomem_resource
= {
42 .flags
= IORESOURCE_MEM
,
44 EXPORT_SYMBOL(iomem_resource
);
46 /* constraints to be met while allocating resources */
47 struct resource_constraint
{
48 resource_size_t min
, max
, align
;
49 resource_size_t (*alignf
)(void *, const struct resource
*,
50 resource_size_t
, resource_size_t
);
54 static DEFINE_RWLOCK(resource_lock
);
57 * For memory hotplug, there is no way to free resource entries allocated
58 * by boot mem after the system is up. So for reusing the resource entry
59 * we need to remember the resource.
61 static struct resource
*bootmem_resource_free
;
62 static DEFINE_SPINLOCK(bootmem_resource_lock
);
64 static struct resource
*next_resource(struct resource
*p
, bool sibling_only
)
66 /* Caller wants to traverse through siblings only */
72 while (!p
->sibling
&& p
->parent
)
77 static void *r_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
79 struct resource
*p
= v
;
81 return (void *)next_resource(p
, false);
86 enum { MAX_IORES_LEVEL
= 5 };
88 static void *r_start(struct seq_file
*m
, loff_t
*pos
)
89 __acquires(resource_lock
)
91 struct resource
*p
= PDE_DATA(file_inode(m
->file
));
93 read_lock(&resource_lock
);
94 for (p
= p
->child
; p
&& l
< *pos
; p
= r_next(m
, p
, &l
))
99 static void r_stop(struct seq_file
*m
, void *v
)
100 __releases(resource_lock
)
102 read_unlock(&resource_lock
);
105 static int r_show(struct seq_file
*m
, void *v
)
107 struct resource
*root
= PDE_DATA(file_inode(m
->file
));
108 struct resource
*r
= v
, *p
;
109 unsigned long long start
, end
;
110 int width
= root
->end
< 0x10000 ? 4 : 8;
113 for (depth
= 0, p
= r
; depth
< MAX_IORES_LEVEL
; depth
++, p
= p
->parent
)
114 if (p
->parent
== root
)
117 if (file_ns_capable(m
->file
, &init_user_ns
, CAP_SYS_ADMIN
)) {
124 seq_printf(m
, "%*s%0*llx-%0*llx : %s\n",
128 r
->name
? r
->name
: "<BAD>");
132 static const struct seq_operations resource_op
= {
139 static int __init
ioresources_init(void)
141 proc_create_seq_data("ioports", 0, NULL
, &resource_op
,
143 proc_create_seq_data("iomem", 0, NULL
, &resource_op
, &iomem_resource
);
146 __initcall(ioresources_init
);
148 #endif /* CONFIG_PROC_FS */
150 static void free_resource(struct resource
*res
)
155 if (!PageSlab(virt_to_head_page(res
))) {
156 spin_lock(&bootmem_resource_lock
);
157 res
->sibling
= bootmem_resource_free
;
158 bootmem_resource_free
= res
;
159 spin_unlock(&bootmem_resource_lock
);
165 static struct resource
*alloc_resource(gfp_t flags
)
167 struct resource
*res
= NULL
;
169 spin_lock(&bootmem_resource_lock
);
170 if (bootmem_resource_free
) {
171 res
= bootmem_resource_free
;
172 bootmem_resource_free
= res
->sibling
;
174 spin_unlock(&bootmem_resource_lock
);
177 memset(res
, 0, sizeof(struct resource
));
179 res
= kzalloc(sizeof(struct resource
), flags
);
184 /* Return the conflict entry if you can't request it */
185 static struct resource
* __request_resource(struct resource
*root
, struct resource
*new)
187 resource_size_t start
= new->start
;
188 resource_size_t end
= new->end
;
189 struct resource
*tmp
, **p
;
193 if (start
< root
->start
)
200 if (!tmp
|| tmp
->start
> end
) {
207 if (tmp
->end
< start
)
213 static int __release_resource(struct resource
*old
, bool release_child
)
215 struct resource
*tmp
, **p
, *chd
;
217 p
= &old
->parent
->child
;
223 if (release_child
|| !(tmp
->child
)) {
226 for (chd
= tmp
->child
;; chd
= chd
->sibling
) {
227 chd
->parent
= tmp
->parent
;
232 chd
->sibling
= tmp
->sibling
;
242 static void __release_child_resources(struct resource
*r
)
244 struct resource
*tmp
, *p
;
245 resource_size_t size
;
255 __release_child_resources(tmp
);
257 printk(KERN_DEBUG
"release child resource %pR\n", tmp
);
258 /* need to restore size, and keep flags */
259 size
= resource_size(tmp
);
265 void release_child_resources(struct resource
*r
)
267 write_lock(&resource_lock
);
268 __release_child_resources(r
);
269 write_unlock(&resource_lock
);
273 * request_resource_conflict - request and reserve an I/O or memory resource
274 * @root: root resource descriptor
275 * @new: resource descriptor desired by caller
277 * Returns 0 for success, conflict resource on error.
279 struct resource
*request_resource_conflict(struct resource
*root
, struct resource
*new)
281 struct resource
*conflict
;
283 write_lock(&resource_lock
);
284 conflict
= __request_resource(root
, new);
285 write_unlock(&resource_lock
);
290 * request_resource - request and reserve an I/O or memory resource
291 * @root: root resource descriptor
292 * @new: resource descriptor desired by caller
294 * Returns 0 for success, negative error code on error.
296 int request_resource(struct resource
*root
, struct resource
*new)
298 struct resource
*conflict
;
300 conflict
= request_resource_conflict(root
, new);
301 return conflict
? -EBUSY
: 0;
304 EXPORT_SYMBOL(request_resource
);
307 * release_resource - release a previously reserved resource
308 * @old: resource pointer
310 int release_resource(struct resource
*old
)
314 write_lock(&resource_lock
);
315 retval
= __release_resource(old
, true);
316 write_unlock(&resource_lock
);
320 EXPORT_SYMBOL(release_resource
);
323 * Finds the lowest iomem resource that covers part of [@start..@end]. The
324 * caller must specify @start, @end, @flags, and @desc (which may be
327 * If a resource is found, returns 0 and @*res is overwritten with the part
328 * of the resource that's within [@start..@end]; if none is found, returns
329 * -ENODEV. Returns -EINVAL for invalid parameters.
331 * This function walks the whole tree and not just first level children
332 * unless @first_lvl is true.
334 * @start: start address of the resource searched for
335 * @end: end address of same resource
336 * @flags: flags which the resource must have
337 * @desc: descriptor the resource must have
338 * @first_lvl: walk only the first level children, if set
339 * @res: return ptr, if resource found
341 static int find_next_iomem_res(resource_size_t start
, resource_size_t end
,
342 unsigned long flags
, unsigned long desc
,
343 bool first_lvl
, struct resource
*res
)
345 bool siblings_only
= true;
354 read_lock(&resource_lock
);
356 for (p
= iomem_resource
.child
; p
; p
= next_resource(p
, siblings_only
)) {
357 /* If we passed the resource we are looking for, stop */
358 if (p
->start
> end
) {
363 /* Skip until we find a range that matches what we look for */
368 * Now that we found a range that matches what we look for,
369 * check the flags and the descriptor. If we were not asked to
370 * use only the first level, start looking at children as well.
372 siblings_only
= first_lvl
;
374 if ((p
->flags
& flags
) != flags
)
376 if ((desc
!= IORES_DESC_NONE
) && (desc
!= p
->desc
))
379 /* Found a match, break */
385 *res
= (struct resource
) {
386 .start
= max(start
, p
->start
),
387 .end
= min(end
, p
->end
),
394 read_unlock(&resource_lock
);
395 return p
? 0 : -ENODEV
;
398 static int __walk_iomem_res_desc(resource_size_t start
, resource_size_t end
,
399 unsigned long flags
, unsigned long desc
,
400 bool first_lvl
, void *arg
,
401 int (*func
)(struct resource
*, void *))
406 while (start
< end
&&
407 !find_next_iomem_res(start
, end
, flags
, desc
, first_lvl
, &res
)) {
408 ret
= (*func
)(&res
, arg
);
419 * Walks through iomem resources and calls func() with matching resource
420 * ranges. This walks through whole tree and not just first level children.
421 * All the memory ranges which overlap start,end and also match flags and
422 * desc are valid candidates.
424 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
425 * @flags: I/O resource flags
428 * @arg: function argument for the callback @func
429 * @func: callback function that is called for each qualifying resource area
431 * NOTE: For a new descriptor search, define a new IORES_DESC in
432 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
434 int walk_iomem_res_desc(unsigned long desc
, unsigned long flags
, u64 start
,
435 u64 end
, void *arg
, int (*func
)(struct resource
*, void *))
437 return __walk_iomem_res_desc(start
, end
, flags
, desc
, false, arg
, func
);
439 EXPORT_SYMBOL_GPL(walk_iomem_res_desc
);
442 * This function calls the @func callback against all memory ranges of type
443 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
444 * Now, this function is only for System RAM, it deals with full ranges and
445 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
448 int walk_system_ram_res(u64 start
, u64 end
, void *arg
,
449 int (*func
)(struct resource
*, void *))
451 unsigned long flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
453 return __walk_iomem_res_desc(start
, end
, flags
, IORES_DESC_NONE
, true,
458 * This function calls the @func callback against all memory ranges, which
459 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
461 int walk_mem_res(u64 start
, u64 end
, void *arg
,
462 int (*func
)(struct resource
*, void *))
464 unsigned long flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
466 return __walk_iomem_res_desc(start
, end
, flags
, IORES_DESC_NONE
, true,
471 * This function calls the @func callback against all memory ranges of type
472 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
473 * It is to be used only for System RAM.
475 * This will find System RAM ranges that are children of top-level resources
476 * in addition to top-level System RAM resources.
478 int walk_system_ram_range(unsigned long start_pfn
, unsigned long nr_pages
,
479 void *arg
, int (*func
)(unsigned long, unsigned long, void *))
481 resource_size_t start
, end
;
484 unsigned long pfn
, end_pfn
;
487 start
= (u64
) start_pfn
<< PAGE_SHIFT
;
488 end
= ((u64
)(start_pfn
+ nr_pages
) << PAGE_SHIFT
) - 1;
489 flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
490 while (start
< end
&&
491 !find_next_iomem_res(start
, end
, flags
, IORES_DESC_NONE
,
493 pfn
= PFN_UP(res
.start
);
494 end_pfn
= PFN_DOWN(res
.end
+ 1);
496 ret
= (*func
)(pfn
, end_pfn
- pfn
, arg
);
504 static int __is_ram(unsigned long pfn
, unsigned long nr_pages
, void *arg
)
510 * This generic page_is_ram() returns true if specified address is
511 * registered as System RAM in iomem_resource list.
513 int __weak
page_is_ram(unsigned long pfn
)
515 return walk_system_ram_range(pfn
, 1, NULL
, __is_ram
) == 1;
517 EXPORT_SYMBOL_GPL(page_is_ram
);
520 * region_intersects() - determine intersection of region with known resources
521 * @start: region start address
522 * @size: size of region
523 * @flags: flags of resource (in iomem_resource)
524 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
526 * Check if the specified region partially overlaps or fully eclipses a
527 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
528 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
529 * return REGION_MIXED if the region overlaps @flags/@desc and another
530 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
531 * and no other defined resource. Note that REGION_INTERSECTS is also
532 * returned in the case when the specified region overlaps RAM and undefined
535 * region_intersect() is used by memory remapping functions to ensure
536 * the user is not remapping RAM and is a vast speed up over walking
537 * through the resource table page by page.
539 int region_intersects(resource_size_t start
, size_t size
, unsigned long flags
,
543 int type
= 0; int other
= 0;
547 res
.end
= start
+ size
- 1;
549 read_lock(&resource_lock
);
550 for (p
= iomem_resource
.child
; p
; p
= p
->sibling
) {
551 bool is_type
= (((p
->flags
& flags
) == flags
) &&
552 ((desc
== IORES_DESC_NONE
) ||
555 if (resource_overlaps(p
, &res
))
556 is_type
? type
++ : other
++;
558 read_unlock(&resource_lock
);
561 return type
? REGION_INTERSECTS
: REGION_DISJOINT
;
566 return REGION_DISJOINT
;
568 EXPORT_SYMBOL_GPL(region_intersects
);
570 void __weak
arch_remove_reservations(struct resource
*avail
)
574 static resource_size_t
simple_align_resource(void *data
,
575 const struct resource
*avail
,
576 resource_size_t size
,
577 resource_size_t align
)
582 static void resource_clip(struct resource
*res
, resource_size_t min
,
585 if (res
->start
< min
)
592 * Find empty slot in the resource tree with the given range and
593 * alignment constraints
595 static int __find_resource(struct resource
*root
, struct resource
*old
,
596 struct resource
*new,
597 resource_size_t size
,
598 struct resource_constraint
*constraint
)
600 struct resource
*this = root
->child
;
601 struct resource tmp
= *new, avail
, alloc
;
603 tmp
.start
= root
->start
;
605 * Skip past an allocated resource that starts at 0, since the assignment
606 * of this->start - 1 to tmp->end below would cause an underflow.
608 if (this && this->start
== root
->start
) {
609 tmp
.start
= (this == old
) ? old
->start
: this->end
+ 1;
610 this = this->sibling
;
614 tmp
.end
= (this == old
) ? this->end
: this->start
- 1;
618 if (tmp
.end
< tmp
.start
)
621 resource_clip(&tmp
, constraint
->min
, constraint
->max
);
622 arch_remove_reservations(&tmp
);
624 /* Check for overflow after ALIGN() */
625 avail
.start
= ALIGN(tmp
.start
, constraint
->align
);
627 avail
.flags
= new->flags
& ~IORESOURCE_UNSET
;
628 if (avail
.start
>= tmp
.start
) {
629 alloc
.flags
= avail
.flags
;
630 alloc
.start
= constraint
->alignf(constraint
->alignf_data
, &avail
,
631 size
, constraint
->align
);
632 alloc
.end
= alloc
.start
+ size
- 1;
633 if (alloc
.start
<= alloc
.end
&&
634 resource_contains(&avail
, &alloc
)) {
635 new->start
= alloc
.start
;
636 new->end
= alloc
.end
;
641 next
: if (!this || this->end
== root
->end
)
645 tmp
.start
= this->end
+ 1;
646 this = this->sibling
;
652 * Find empty slot in the resource tree given range and alignment.
654 static int find_resource(struct resource
*root
, struct resource
*new,
655 resource_size_t size
,
656 struct resource_constraint
*constraint
)
658 return __find_resource(root
, NULL
, new, size
, constraint
);
662 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
663 * The resource will be relocated if the new size cannot be reallocated in the
666 * @root: root resource descriptor
667 * @old: resource descriptor desired by caller
668 * @newsize: new size of the resource descriptor
669 * @constraint: the size and alignment constraints to be met.
671 static int reallocate_resource(struct resource
*root
, struct resource
*old
,
672 resource_size_t newsize
,
673 struct resource_constraint
*constraint
)
676 struct resource
new = *old
;
677 struct resource
*conflict
;
679 write_lock(&resource_lock
);
681 if ((err
= __find_resource(root
, old
, &new, newsize
, constraint
)))
684 if (resource_contains(&new, old
)) {
685 old
->start
= new.start
;
695 if (resource_contains(old
, &new)) {
696 old
->start
= new.start
;
699 __release_resource(old
, true);
701 conflict
= __request_resource(root
, old
);
705 write_unlock(&resource_lock
);
711 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
712 * The resource will be reallocated with a new size if it was already allocated
713 * @root: root resource descriptor
714 * @new: resource descriptor desired by caller
715 * @size: requested resource region size
716 * @min: minimum boundary to allocate
717 * @max: maximum boundary to allocate
718 * @align: alignment requested, in bytes
719 * @alignf: alignment function, optional, called if not NULL
720 * @alignf_data: arbitrary data to pass to the @alignf function
722 int allocate_resource(struct resource
*root
, struct resource
*new,
723 resource_size_t size
, resource_size_t min
,
724 resource_size_t max
, resource_size_t align
,
725 resource_size_t (*alignf
)(void *,
726 const struct resource
*,
732 struct resource_constraint constraint
;
735 alignf
= simple_align_resource
;
737 constraint
.min
= min
;
738 constraint
.max
= max
;
739 constraint
.align
= align
;
740 constraint
.alignf
= alignf
;
741 constraint
.alignf_data
= alignf_data
;
744 /* resource is already allocated, try reallocating with
745 the new constraints */
746 return reallocate_resource(root
, new, size
, &constraint
);
749 write_lock(&resource_lock
);
750 err
= find_resource(root
, new, size
, &constraint
);
751 if (err
>= 0 && __request_resource(root
, new))
753 write_unlock(&resource_lock
);
757 EXPORT_SYMBOL(allocate_resource
);
760 * lookup_resource - find an existing resource by a resource start address
761 * @root: root resource descriptor
762 * @start: resource start address
764 * Returns a pointer to the resource if found, NULL otherwise
766 struct resource
*lookup_resource(struct resource
*root
, resource_size_t start
)
768 struct resource
*res
;
770 read_lock(&resource_lock
);
771 for (res
= root
->child
; res
; res
= res
->sibling
) {
772 if (res
->start
== start
)
775 read_unlock(&resource_lock
);
781 * Insert a resource into the resource tree. If successful, return NULL,
782 * otherwise return the conflicting resource (compare to __request_resource())
784 static struct resource
* __insert_resource(struct resource
*parent
, struct resource
*new)
786 struct resource
*first
, *next
;
788 for (;; parent
= first
) {
789 first
= __request_resource(parent
, new);
795 if (WARN_ON(first
== new)) /* duplicated insertion */
798 if ((first
->start
> new->start
) || (first
->end
< new->end
))
800 if ((first
->start
== new->start
) && (first
->end
== new->end
))
804 for (next
= first
; ; next
= next
->sibling
) {
805 /* Partial overlap? Bad, and unfixable */
806 if (next
->start
< new->start
|| next
->end
> new->end
)
810 if (next
->sibling
->start
> new->end
)
814 new->parent
= parent
;
815 new->sibling
= next
->sibling
;
818 next
->sibling
= NULL
;
819 for (next
= first
; next
; next
= next
->sibling
)
822 if (parent
->child
== first
) {
825 next
= parent
->child
;
826 while (next
->sibling
!= first
)
827 next
= next
->sibling
;
834 * insert_resource_conflict - Inserts resource in the resource tree
835 * @parent: parent of the new resource
836 * @new: new resource to insert
838 * Returns 0 on success, conflict resource if the resource can't be inserted.
840 * This function is equivalent to request_resource_conflict when no conflict
841 * happens. If a conflict happens, and the conflicting resources
842 * entirely fit within the range of the new resource, then the new
843 * resource is inserted and the conflicting resources become children of
846 * This function is intended for producers of resources, such as FW modules
849 struct resource
*insert_resource_conflict(struct resource
*parent
, struct resource
*new)
851 struct resource
*conflict
;
853 write_lock(&resource_lock
);
854 conflict
= __insert_resource(parent
, new);
855 write_unlock(&resource_lock
);
860 * insert_resource - Inserts a resource in the resource tree
861 * @parent: parent of the new resource
862 * @new: new resource to insert
864 * Returns 0 on success, -EBUSY if the resource can't be inserted.
866 * This function is intended for producers of resources, such as FW modules
869 int insert_resource(struct resource
*parent
, struct resource
*new)
871 struct resource
*conflict
;
873 conflict
= insert_resource_conflict(parent
, new);
874 return conflict
? -EBUSY
: 0;
876 EXPORT_SYMBOL_GPL(insert_resource
);
879 * insert_resource_expand_to_fit - Insert a resource into the resource tree
880 * @root: root resource descriptor
881 * @new: new resource to insert
883 * Insert a resource into the resource tree, possibly expanding it in order
884 * to make it encompass any conflicting resources.
886 void insert_resource_expand_to_fit(struct resource
*root
, struct resource
*new)
891 write_lock(&resource_lock
);
893 struct resource
*conflict
;
895 conflict
= __insert_resource(root
, new);
898 if (conflict
== root
)
901 /* Ok, expand resource to cover the conflict, then try again .. */
902 if (conflict
->start
< new->start
)
903 new->start
= conflict
->start
;
904 if (conflict
->end
> new->end
)
905 new->end
= conflict
->end
;
907 printk("Expanded resource %s due to conflict with %s\n", new->name
, conflict
->name
);
909 write_unlock(&resource_lock
);
913 * remove_resource - Remove a resource in the resource tree
914 * @old: resource to remove
916 * Returns 0 on success, -EINVAL if the resource is not valid.
918 * This function removes a resource previously inserted by insert_resource()
919 * or insert_resource_conflict(), and moves the children (if any) up to
920 * where they were before. insert_resource() and insert_resource_conflict()
921 * insert a new resource, and move any conflicting resources down to the
922 * children of the new resource.
924 * insert_resource(), insert_resource_conflict() and remove_resource() are
925 * intended for producers of resources, such as FW modules and bus drivers.
927 int remove_resource(struct resource
*old
)
931 write_lock(&resource_lock
);
932 retval
= __release_resource(old
, false);
933 write_unlock(&resource_lock
);
936 EXPORT_SYMBOL_GPL(remove_resource
);
938 static int __adjust_resource(struct resource
*res
, resource_size_t start
,
939 resource_size_t size
)
941 struct resource
*tmp
, *parent
= res
->parent
;
942 resource_size_t end
= start
+ size
- 1;
948 if ((start
< parent
->start
) || (end
> parent
->end
))
951 if (res
->sibling
&& (res
->sibling
->start
<= end
))
956 while (tmp
->sibling
!= res
)
958 if (start
<= tmp
->end
)
963 for (tmp
= res
->child
; tmp
; tmp
= tmp
->sibling
)
964 if ((tmp
->start
< start
) || (tmp
->end
> end
))
976 * adjust_resource - modify a resource's start and size
977 * @res: resource to modify
978 * @start: new start value
981 * Given an existing resource, change its start and size to match the
982 * arguments. Returns 0 on success, -EBUSY if it can't fit.
983 * Existing children of the resource are assumed to be immutable.
985 int adjust_resource(struct resource
*res
, resource_size_t start
,
986 resource_size_t size
)
990 write_lock(&resource_lock
);
991 result
= __adjust_resource(res
, start
, size
);
992 write_unlock(&resource_lock
);
995 EXPORT_SYMBOL(adjust_resource
);
998 __reserve_region_with_split(struct resource
*root
, resource_size_t start
,
999 resource_size_t end
, const char *name
)
1001 struct resource
*parent
= root
;
1002 struct resource
*conflict
;
1003 struct resource
*res
= alloc_resource(GFP_ATOMIC
);
1004 struct resource
*next_res
= NULL
;
1005 int type
= resource_type(root
);
1013 res
->flags
= type
| IORESOURCE_BUSY
;
1014 res
->desc
= IORES_DESC_NONE
;
1018 conflict
= __request_resource(parent
, res
);
1027 /* conflict covered whole area */
1028 if (conflict
->start
<= res
->start
&&
1029 conflict
->end
>= res
->end
) {
1035 /* failed, split and try again */
1036 if (conflict
->start
> res
->start
) {
1038 res
->end
= conflict
->start
- 1;
1039 if (conflict
->end
< end
) {
1040 next_res
= alloc_resource(GFP_ATOMIC
);
1045 next_res
->name
= name
;
1046 next_res
->start
= conflict
->end
+ 1;
1047 next_res
->end
= end
;
1048 next_res
->flags
= type
| IORESOURCE_BUSY
;
1049 next_res
->desc
= IORES_DESC_NONE
;
1052 res
->start
= conflict
->end
+ 1;
1059 reserve_region_with_split(struct resource
*root
, resource_size_t start
,
1060 resource_size_t end
, const char *name
)
1064 write_lock(&resource_lock
);
1065 if (root
->start
> start
|| root
->end
< end
) {
1066 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1067 (unsigned long long)start
, (unsigned long long)end
,
1069 if (start
> root
->end
|| end
< root
->start
)
1072 if (end
> root
->end
)
1074 if (start
< root
->start
)
1075 start
= root
->start
;
1076 pr_err("fixing request to [0x%llx-0x%llx]\n",
1077 (unsigned long long)start
,
1078 (unsigned long long)end
);
1083 __reserve_region_with_split(root
, start
, end
, name
);
1084 write_unlock(&resource_lock
);
1088 * resource_alignment - calculate resource's alignment
1089 * @res: resource pointer
1091 * Returns alignment on success, 0 (invalid alignment) on failure.
1093 resource_size_t
resource_alignment(struct resource
*res
)
1095 switch (res
->flags
& (IORESOURCE_SIZEALIGN
| IORESOURCE_STARTALIGN
)) {
1096 case IORESOURCE_SIZEALIGN
:
1097 return resource_size(res
);
1098 case IORESOURCE_STARTALIGN
:
1106 * This is compatibility stuff for IO resources.
1108 * Note how this, unlike the above, knows about
1109 * the IO flag meanings (busy etc).
1111 * request_region creates a new busy region.
1113 * release_region releases a matching busy region.
1116 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait
);
1119 * __request_region - create a new busy resource region
1120 * @parent: parent resource descriptor
1121 * @start: resource start address
1122 * @n: resource region size
1123 * @name: reserving caller's ID string
1124 * @flags: IO resource flags
1126 struct resource
* __request_region(struct resource
*parent
,
1127 resource_size_t start
, resource_size_t n
,
1128 const char *name
, int flags
)
1130 DECLARE_WAITQUEUE(wait
, current
);
1131 struct resource
*res
= alloc_resource(GFP_KERNEL
);
1132 struct resource
*orig_parent
= parent
;
1139 res
->end
= start
+ n
- 1;
1141 write_lock(&resource_lock
);
1144 struct resource
*conflict
;
1146 res
->flags
= resource_type(parent
) | resource_ext_type(parent
);
1147 res
->flags
|= IORESOURCE_BUSY
| flags
;
1148 res
->desc
= parent
->desc
;
1150 conflict
= __request_resource(parent
, res
);
1154 * mm/hmm.c reserves physical addresses which then
1155 * become unavailable to other users. Conflicts are
1156 * not expected. Warn to aid debugging if encountered.
1158 if (conflict
->desc
== IORES_DESC_DEVICE_PRIVATE_MEMORY
) {
1159 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1160 conflict
->name
, conflict
, res
);
1162 if (conflict
!= parent
) {
1163 if (!(conflict
->flags
& IORESOURCE_BUSY
)) {
1168 if (conflict
->flags
& flags
& IORESOURCE_MUXED
) {
1169 add_wait_queue(&muxed_resource_wait
, &wait
);
1170 write_unlock(&resource_lock
);
1171 set_current_state(TASK_UNINTERRUPTIBLE
);
1173 remove_wait_queue(&muxed_resource_wait
, &wait
);
1174 write_lock(&resource_lock
);
1177 /* Uhhuh, that didn't work out.. */
1182 write_unlock(&resource_lock
);
1184 if (res
&& orig_parent
== &iomem_resource
)
1189 EXPORT_SYMBOL(__request_region
);
1192 * __release_region - release a previously reserved resource region
1193 * @parent: parent resource descriptor
1194 * @start: resource start address
1195 * @n: resource region size
1197 * The described resource region must match a currently busy region.
1199 void __release_region(struct resource
*parent
, resource_size_t start
,
1202 struct resource
**p
;
1203 resource_size_t end
;
1206 end
= start
+ n
- 1;
1208 write_lock(&resource_lock
);
1211 struct resource
*res
= *p
;
1215 if (res
->start
<= start
&& res
->end
>= end
) {
1216 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1220 if (res
->start
!= start
|| res
->end
!= end
)
1223 write_unlock(&resource_lock
);
1224 if (res
->flags
& IORESOURCE_MUXED
)
1225 wake_up(&muxed_resource_wait
);
1232 write_unlock(&resource_lock
);
1234 printk(KERN_WARNING
"Trying to free nonexistent resource "
1235 "<%016llx-%016llx>\n", (unsigned long long)start
,
1236 (unsigned long long)end
);
1238 EXPORT_SYMBOL(__release_region
);
1240 #ifdef CONFIG_MEMORY_HOTREMOVE
1242 * release_mem_region_adjustable - release a previously reserved memory region
1243 * @start: resource start address
1244 * @size: resource region size
1246 * This interface is intended for memory hot-delete. The requested region
1247 * is released from a currently busy memory resource. The requested region
1248 * must either match exactly or fit into a single busy resource entry. In
1249 * the latter case, the remaining resource is adjusted accordingly.
1250 * Existing children of the busy memory resource must be immutable in the
1254 * - Additional release conditions, such as overlapping region, can be
1255 * supported after they are confirmed as valid cases.
1256 * - When a busy memory resource gets split into two entries, the code
1257 * assumes that all children remain in the lower address entry for
1258 * simplicity. Enhance this logic when necessary.
1260 void release_mem_region_adjustable(resource_size_t start
, resource_size_t size
)
1262 struct resource
*parent
= &iomem_resource
;
1263 struct resource
*new_res
= NULL
;
1264 bool alloc_nofail
= false;
1265 struct resource
**p
;
1266 struct resource
*res
;
1267 resource_size_t end
;
1269 end
= start
+ size
- 1;
1270 if (WARN_ON_ONCE((start
< parent
->start
) || (end
> parent
->end
)))
1274 * We free up quite a lot of memory on memory hotunplug (esp., memap),
1275 * just before releasing the region. This is highly unlikely to
1276 * fail - let's play save and make it never fail as the caller cannot
1277 * perform any error handling (e.g., trying to re-add memory will fail
1281 new_res
= alloc_resource(GFP_KERNEL
| (alloc_nofail
? __GFP_NOFAIL
: 0));
1284 write_lock(&resource_lock
);
1286 while ((res
= *p
)) {
1287 if (res
->start
>= end
)
1290 /* look for the next resource if it does not fit into */
1291 if (res
->start
> start
|| res
->end
< end
) {
1297 * All memory regions added from memory-hotplug path have the
1298 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1299 * this flag, we know that we are dealing with a resource coming
1300 * from HMM/devm. HMM/devm use another mechanism to add/release
1301 * a resource. This goes via devm_request_mem_region and
1302 * devm_release_mem_region.
1303 * HMM/devm take care to release their resources when they want,
1304 * so if we are dealing with them, let us just back off here.
1306 if (!(res
->flags
& IORESOURCE_SYSRAM
)) {
1310 if (!(res
->flags
& IORESOURCE_MEM
))
1313 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1318 /* found the target resource; let's adjust accordingly */
1319 if (res
->start
== start
&& res
->end
== end
) {
1320 /* free the whole entry */
1323 } else if (res
->start
== start
&& res
->end
!= end
) {
1324 /* adjust the start */
1325 WARN_ON_ONCE(__adjust_resource(res
, end
+ 1,
1327 } else if (res
->start
!= start
&& res
->end
== end
) {
1328 /* adjust the end */
1329 WARN_ON_ONCE(__adjust_resource(res
, res
->start
,
1330 start
- res
->start
));
1332 /* split into two entries - we need a new resource */
1334 new_res
= alloc_resource(GFP_ATOMIC
);
1336 alloc_nofail
= true;
1337 write_unlock(&resource_lock
);
1341 new_res
->name
= res
->name
;
1342 new_res
->start
= end
+ 1;
1343 new_res
->end
= res
->end
;
1344 new_res
->flags
= res
->flags
;
1345 new_res
->desc
= res
->desc
;
1346 new_res
->parent
= res
->parent
;
1347 new_res
->sibling
= res
->sibling
;
1348 new_res
->child
= NULL
;
1350 if (WARN_ON_ONCE(__adjust_resource(res
, res
->start
,
1351 start
- res
->start
)))
1353 res
->sibling
= new_res
;
1360 write_unlock(&resource_lock
);
1361 free_resource(new_res
);
1363 #endif /* CONFIG_MEMORY_HOTREMOVE */
1365 #ifdef CONFIG_MEMORY_HOTPLUG
1366 static bool system_ram_resources_mergeable(struct resource
*r1
,
1367 struct resource
*r2
)
1369 /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1370 return r1
->flags
== r2
->flags
&& r1
->end
+ 1 == r2
->start
&&
1371 r1
->name
== r2
->name
&& r1
->desc
== r2
->desc
&&
1372 !r1
->child
&& !r2
->child
;
1376 * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1377 * merge it with adjacent, mergeable resources
1378 * @res: resource descriptor
1380 * This interface is intended for memory hotplug, whereby lots of contiguous
1381 * system ram resources are added (e.g., via add_memory*()) by a driver, and
1382 * the actual resource boundaries are not of interest (e.g., it might be
1383 * relevant for DIMMs). Only resources that are marked mergeable, that have the
1384 * same parent, and that don't have any children are considered. All mergeable
1385 * resources must be immutable during the request.
1388 * - The caller has to make sure that no pointers to resources that are
1389 * marked mergeable are used anymore after this call - the resource might
1390 * be freed and the pointer might be stale!
1391 * - release_mem_region_adjustable() will split on demand on memory hotunplug
1393 void merge_system_ram_resource(struct resource
*res
)
1395 const unsigned long flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
1396 struct resource
*cur
;
1398 if (WARN_ON_ONCE((res
->flags
& flags
) != flags
))
1401 write_lock(&resource_lock
);
1402 res
->flags
|= IORESOURCE_SYSRAM_MERGEABLE
;
1404 /* Try to merge with next item in the list. */
1406 if (cur
&& system_ram_resources_mergeable(res
, cur
)) {
1407 res
->end
= cur
->end
;
1408 res
->sibling
= cur
->sibling
;
1412 /* Try to merge with previous item in the list. */
1413 cur
= res
->parent
->child
;
1414 while (cur
&& cur
->sibling
!= res
)
1416 if (cur
&& system_ram_resources_mergeable(cur
, res
)) {
1417 cur
->end
= res
->end
;
1418 cur
->sibling
= res
->sibling
;
1421 write_unlock(&resource_lock
);
1423 #endif /* CONFIG_MEMORY_HOTPLUG */
1426 * Managed region resource
1428 static void devm_resource_release(struct device
*dev
, void *ptr
)
1430 struct resource
**r
= ptr
;
1432 release_resource(*r
);
1436 * devm_request_resource() - request and reserve an I/O or memory resource
1437 * @dev: device for which to request the resource
1438 * @root: root of the resource tree from which to request the resource
1439 * @new: descriptor of the resource to request
1441 * This is a device-managed version of request_resource(). There is usually
1442 * no need to release resources requested by this function explicitly since
1443 * that will be taken care of when the device is unbound from its driver.
1444 * If for some reason the resource needs to be released explicitly, because
1445 * of ordering issues for example, drivers must call devm_release_resource()
1446 * rather than the regular release_resource().
1448 * When a conflict is detected between any existing resources and the newly
1449 * requested resource, an error message will be printed.
1451 * Returns 0 on success or a negative error code on failure.
1453 int devm_request_resource(struct device
*dev
, struct resource
*root
,
1454 struct resource
*new)
1456 struct resource
*conflict
, **ptr
;
1458 ptr
= devres_alloc(devm_resource_release
, sizeof(*ptr
), GFP_KERNEL
);
1464 conflict
= request_resource_conflict(root
, new);
1466 dev_err(dev
, "resource collision: %pR conflicts with %s %pR\n",
1467 new, conflict
->name
, conflict
);
1472 devres_add(dev
, ptr
);
1475 EXPORT_SYMBOL(devm_request_resource
);
1477 static int devm_resource_match(struct device
*dev
, void *res
, void *data
)
1479 struct resource
**ptr
= res
;
1481 return *ptr
== data
;
1485 * devm_release_resource() - release a previously requested resource
1486 * @dev: device for which to release the resource
1487 * @new: descriptor of the resource to release
1489 * Releases a resource previously requested using devm_request_resource().
1491 void devm_release_resource(struct device
*dev
, struct resource
*new)
1493 WARN_ON(devres_release(dev
, devm_resource_release
, devm_resource_match
,
1496 EXPORT_SYMBOL(devm_release_resource
);
1498 struct region_devres
{
1499 struct resource
*parent
;
1500 resource_size_t start
;
1504 static void devm_region_release(struct device
*dev
, void *res
)
1506 struct region_devres
*this = res
;
1508 __release_region(this->parent
, this->start
, this->n
);
1511 static int devm_region_match(struct device
*dev
, void *res
, void *match_data
)
1513 struct region_devres
*this = res
, *match
= match_data
;
1515 return this->parent
== match
->parent
&&
1516 this->start
== match
->start
&& this->n
== match
->n
;
1520 __devm_request_region(struct device
*dev
, struct resource
*parent
,
1521 resource_size_t start
, resource_size_t n
, const char *name
)
1523 struct region_devres
*dr
= NULL
;
1524 struct resource
*res
;
1526 dr
= devres_alloc(devm_region_release
, sizeof(struct region_devres
),
1531 dr
->parent
= parent
;
1535 res
= __request_region(parent
, start
, n
, name
, 0);
1537 devres_add(dev
, dr
);
1543 EXPORT_SYMBOL(__devm_request_region
);
1545 void __devm_release_region(struct device
*dev
, struct resource
*parent
,
1546 resource_size_t start
, resource_size_t n
)
1548 struct region_devres match_data
= { parent
, start
, n
};
1550 __release_region(parent
, start
, n
);
1551 WARN_ON(devres_destroy(dev
, devm_region_release
, devm_region_match
,
1554 EXPORT_SYMBOL(__devm_release_region
);
1557 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1559 #define MAXRESERVE 4
1560 static int __init
reserve_setup(char *str
)
1562 static int reserved
;
1563 static struct resource reserve
[MAXRESERVE
];
1566 unsigned int io_start
, io_num
;
1568 struct resource
*parent
;
1570 if (get_option(&str
, &io_start
) != 2)
1572 if (get_option(&str
, &io_num
) == 0)
1574 if (x
< MAXRESERVE
) {
1575 struct resource
*res
= reserve
+ x
;
1578 * If the region starts below 0x10000, we assume it's
1579 * I/O port space; otherwise assume it's memory.
1581 if (io_start
< 0x10000) {
1582 res
->flags
= IORESOURCE_IO
;
1583 parent
= &ioport_resource
;
1585 res
->flags
= IORESOURCE_MEM
;
1586 parent
= &iomem_resource
;
1588 res
->name
= "reserved";
1589 res
->start
= io_start
;
1590 res
->end
= io_start
+ io_num
- 1;
1591 res
->flags
|= IORESOURCE_BUSY
;
1592 res
->desc
= IORES_DESC_NONE
;
1594 if (request_resource(parent
, res
) == 0)
1600 __setup("reserve=", reserve_setup
);
1603 * Check if the requested addr and size spans more than any slot in the
1604 * iomem resource tree.
1606 int iomem_map_sanity_check(resource_size_t addr
, unsigned long size
)
1608 struct resource
*p
= &iomem_resource
;
1612 read_lock(&resource_lock
);
1613 for (p
= p
->child
; p
; p
= r_next(NULL
, p
, &l
)) {
1615 * We can probably skip the resources without
1616 * IORESOURCE_IO attribute?
1618 if (p
->start
>= addr
+ size
)
1622 if (PFN_DOWN(p
->start
) <= PFN_DOWN(addr
) &&
1623 PFN_DOWN(p
->end
) >= PFN_DOWN(addr
+ size
- 1))
1626 * if a resource is "BUSY", it's not a hardware resource
1627 * but a driver mapping of such a resource; we don't want
1628 * to warn for those; some drivers legitimately map only
1629 * partial hardware resources. (example: vesafb)
1631 if (p
->flags
& IORESOURCE_BUSY
)
1634 printk(KERN_WARNING
"resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1635 (unsigned long long)addr
,
1636 (unsigned long long)(addr
+ size
- 1),
1641 read_unlock(&resource_lock
);
1646 #ifdef CONFIG_STRICT_DEVMEM
1647 static int strict_iomem_checks
= 1;
1649 static int strict_iomem_checks
;
1653 * check if an address is reserved in the iomem resource tree
1654 * returns true if reserved, false if not reserved.
1656 bool iomem_is_exclusive(u64 addr
)
1658 struct resource
*p
= &iomem_resource
;
1661 int size
= PAGE_SIZE
;
1663 if (!strict_iomem_checks
)
1666 addr
= addr
& PAGE_MASK
;
1668 read_lock(&resource_lock
);
1669 for (p
= p
->child
; p
; p
= r_next(NULL
, p
, &l
)) {
1671 * We can probably skip the resources without
1672 * IORESOURCE_IO attribute?
1674 if (p
->start
>= addr
+ size
)
1679 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1680 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1683 if ((p
->flags
& IORESOURCE_BUSY
) == 0)
1685 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM
)
1686 || p
->flags
& IORESOURCE_EXCLUSIVE
) {
1691 read_unlock(&resource_lock
);
1696 struct resource_entry
*resource_list_create_entry(struct resource
*res
,
1699 struct resource_entry
*entry
;
1701 entry
= kzalloc(sizeof(*entry
) + extra_size
, GFP_KERNEL
);
1703 INIT_LIST_HEAD(&entry
->node
);
1704 entry
->res
= res
? res
: &entry
->__res
;
1709 EXPORT_SYMBOL(resource_list_create_entry
);
1711 void resource_list_free(struct list_head
*head
)
1713 struct resource_entry
*entry
, *tmp
;
1715 list_for_each_entry_safe(entry
, tmp
, head
, node
)
1716 resource_list_destroy_entry(entry
);
1718 EXPORT_SYMBOL(resource_list_free
);
1720 #ifdef CONFIG_DEVICE_PRIVATE
1721 static struct resource
*__request_free_mem_region(struct device
*dev
,
1722 struct resource
*base
, unsigned long size
, const char *name
)
1724 resource_size_t end
, addr
;
1725 struct resource
*res
;
1727 size
= ALIGN(size
, 1UL << PA_SECTION_SHIFT
);
1728 end
= min_t(unsigned long, base
->end
, (1UL << MAX_PHYSMEM_BITS
) - 1);
1729 addr
= end
- size
+ 1UL;
1731 for (; addr
> size
&& addr
>= base
->start
; addr
-= size
) {
1732 if (region_intersects(addr
, size
, 0, IORES_DESC_NONE
) !=
1737 res
= devm_request_mem_region(dev
, addr
, size
, name
);
1739 res
= request_mem_region(addr
, size
, name
);
1741 return ERR_PTR(-ENOMEM
);
1742 res
->desc
= IORES_DESC_DEVICE_PRIVATE_MEMORY
;
1746 return ERR_PTR(-ERANGE
);
1750 * devm_request_free_mem_region - find free region for device private memory
1752 * @dev: device struct to bind the resource to
1753 * @size: size in bytes of the device memory to add
1754 * @base: resource tree to look in
1756 * This function tries to find an empty range of physical address big enough to
1757 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1758 * memory, which in turn allocates struct pages.
1760 struct resource
*devm_request_free_mem_region(struct device
*dev
,
1761 struct resource
*base
, unsigned long size
)
1763 return __request_free_mem_region(dev
, base
, size
, dev_name(dev
));
1765 EXPORT_SYMBOL_GPL(devm_request_free_mem_region
);
1767 struct resource
*request_free_mem_region(struct resource
*base
,
1768 unsigned long size
, const char *name
)
1770 return __request_free_mem_region(NULL
, base
, size
, name
);
1772 EXPORT_SYMBOL_GPL(request_free_mem_region
);
1774 #endif /* CONFIG_DEVICE_PRIVATE */
1776 static int __init
strict_iomem(char *str
)
1778 if (strstr(str
, "relaxed"))
1779 strict_iomem_checks
= 0;
1780 if (strstr(str
, "strict"))
1781 strict_iomem_checks
= 1;
1785 __setup("iomem=", strict_iomem
);