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/pseudo_fs.h>
22 #include <linux/sched.h>
23 #include <linux/seq_file.h>
24 #include <linux/device.h>
25 #include <linux/pfn.h>
27 #include <linux/mount.h>
28 #include <linux/resource_ext.h>
29 #include <uapi/linux/magic.h>
33 struct resource ioport_resource
= {
36 .end
= IO_SPACE_LIMIT
,
37 .flags
= IORESOURCE_IO
,
39 EXPORT_SYMBOL(ioport_resource
);
41 struct resource iomem_resource
= {
45 .flags
= IORESOURCE_MEM
,
47 EXPORT_SYMBOL(iomem_resource
);
49 /* constraints to be met while allocating resources */
50 struct 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
);
57 static DEFINE_RWLOCK(resource_lock
);
59 static struct resource
*next_resource(struct resource
*p
, bool skip_children
)
61 if (!skip_children
&& p
->child
)
63 while (!p
->sibling
&& p
->parent
)
68 #define for_each_resource(_root, _p, _skip_children) \
69 for ((_p) = (_root)->child; (_p); (_p) = next_resource(_p, _skip_children))
73 enum { MAX_IORES_LEVEL
= 5 };
75 static void *r_start(struct seq_file
*m
, loff_t
*pos
)
76 __acquires(resource_lock
)
78 struct resource
*root
= pde_data(file_inode(m
->file
));
82 read_lock(&resource_lock
);
83 for_each_resource(root
, p
, false) {
91 static void *r_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
93 struct resource
*p
= v
;
97 return (void *)next_resource(p
, false);
100 static void r_stop(struct seq_file
*m
, void *v
)
101 __releases(resource_lock
)
103 read_unlock(&resource_lock
);
106 static int r_show(struct seq_file
*m
, void *v
)
108 struct resource
*root
= pde_data(file_inode(m
->file
));
109 struct resource
*r
= v
, *p
;
110 unsigned long long start
, end
;
111 int width
= root
->end
< 0x10000 ? 4 : 8;
114 for (depth
= 0, p
= r
; depth
< MAX_IORES_LEVEL
; depth
++, p
= p
->parent
)
115 if (p
->parent
== root
)
118 if (file_ns_capable(m
->file
, &init_user_ns
, CAP_SYS_ADMIN
)) {
125 seq_printf(m
, "%*s%0*llx-%0*llx : %s\n",
129 r
->name
? r
->name
: "<BAD>");
133 static const struct seq_operations resource_op
= {
140 static int __init
ioresources_init(void)
142 proc_create_seq_data("ioports", 0, NULL
, &resource_op
,
144 proc_create_seq_data("iomem", 0, NULL
, &resource_op
, &iomem_resource
);
147 __initcall(ioresources_init
);
149 #endif /* CONFIG_PROC_FS */
151 static void free_resource(struct resource
*res
)
154 * If the resource was allocated using memblock early during boot
155 * we'll leak it here: we can only return full pages back to the
156 * buddy and trying to be smart and reusing them eventually in
157 * alloc_resource() overcomplicates resource handling.
159 if (res
&& PageSlab(virt_to_head_page(res
)))
163 static struct resource
*alloc_resource(gfp_t flags
)
165 return kzalloc(sizeof(struct resource
), flags
);
168 /* Return the conflict entry if you can't request it */
169 static struct resource
* __request_resource(struct resource
*root
, struct resource
*new)
171 resource_size_t start
= new->start
;
172 resource_size_t end
= new->end
;
173 struct resource
*tmp
, **p
;
177 if (start
< root
->start
)
184 if (!tmp
|| tmp
->start
> end
) {
191 if (tmp
->end
< start
)
197 static int __release_resource(struct resource
*old
, bool release_child
)
199 struct resource
*tmp
, **p
, *chd
;
201 p
= &old
->parent
->child
;
207 if (release_child
|| !(tmp
->child
)) {
210 for (chd
= tmp
->child
;; chd
= chd
->sibling
) {
211 chd
->parent
= tmp
->parent
;
216 chd
->sibling
= tmp
->sibling
;
226 static void __release_child_resources(struct resource
*r
)
228 struct resource
*tmp
, *p
;
229 resource_size_t size
;
239 __release_child_resources(tmp
);
241 printk(KERN_DEBUG
"release child resource %pR\n", tmp
);
242 /* need to restore size, and keep flags */
243 size
= resource_size(tmp
);
249 void release_child_resources(struct resource
*r
)
251 write_lock(&resource_lock
);
252 __release_child_resources(r
);
253 write_unlock(&resource_lock
);
257 * request_resource_conflict - request and reserve an I/O or memory resource
258 * @root: root resource descriptor
259 * @new: resource descriptor desired by caller
261 * Returns 0 for success, conflict resource on error.
263 struct resource
*request_resource_conflict(struct resource
*root
, struct resource
*new)
265 struct resource
*conflict
;
267 write_lock(&resource_lock
);
268 conflict
= __request_resource(root
, new);
269 write_unlock(&resource_lock
);
274 * request_resource - request and reserve an I/O or memory resource
275 * @root: root resource descriptor
276 * @new: resource descriptor desired by caller
278 * Returns 0 for success, negative error code on error.
280 int request_resource(struct resource
*root
, struct resource
*new)
282 struct resource
*conflict
;
284 conflict
= request_resource_conflict(root
, new);
285 return conflict
? -EBUSY
: 0;
288 EXPORT_SYMBOL(request_resource
);
291 * release_resource - release a previously reserved resource
292 * @old: resource pointer
294 int release_resource(struct resource
*old
)
298 write_lock(&resource_lock
);
299 retval
= __release_resource(old
, true);
300 write_unlock(&resource_lock
);
304 EXPORT_SYMBOL(release_resource
);
307 * find_next_iomem_res - Finds the lowest iomem resource that covers part of
310 * If a resource is found, returns 0 and @*res is overwritten with the part
311 * of the resource that's within [@start..@end]; if none is found, returns
312 * -ENODEV. Returns -EINVAL for invalid parameters.
314 * @start: start address of the resource searched for
315 * @end: end address of same resource
316 * @flags: flags which the resource must have
317 * @desc: descriptor the resource must have
318 * @res: return ptr, if resource found
320 * The caller must specify @start, @end, @flags, and @desc
321 * (which may be IORES_DESC_NONE).
323 static int find_next_iomem_res(resource_size_t start
, resource_size_t end
,
324 unsigned long flags
, unsigned long desc
,
325 struct resource
*res
)
335 read_lock(&resource_lock
);
337 for_each_resource(&iomem_resource
, p
, false) {
338 /* If we passed the resource we are looking for, stop */
339 if (p
->start
> end
) {
344 /* Skip until we find a range that matches what we look for */
348 if ((p
->flags
& flags
) != flags
)
350 if ((desc
!= IORES_DESC_NONE
) && (desc
!= p
->desc
))
353 /* Found a match, break */
359 *res
= (struct resource
) {
360 .start
= max(start
, p
->start
),
361 .end
= min(end
, p
->end
),
368 read_unlock(&resource_lock
);
369 return p
? 0 : -ENODEV
;
372 static int __walk_iomem_res_desc(resource_size_t start
, resource_size_t end
,
373 unsigned long flags
, unsigned long desc
,
375 int (*func
)(struct resource
*, void *))
380 while (start
< end
&&
381 !find_next_iomem_res(start
, end
, flags
, desc
, &res
)) {
382 ret
= (*func
)(&res
, arg
);
393 * walk_iomem_res_desc - Walks through iomem resources and calls func()
394 * with matching resource ranges.
396 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
397 * @flags: I/O resource flags
400 * @arg: function argument for the callback @func
401 * @func: callback function that is called for each qualifying resource area
403 * All the memory ranges which overlap start,end and also match flags and
404 * desc are valid candidates.
406 * NOTE: For a new descriptor search, define a new IORES_DESC in
407 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
409 int walk_iomem_res_desc(unsigned long desc
, unsigned long flags
, u64 start
,
410 u64 end
, void *arg
, int (*func
)(struct resource
*, void *))
412 return __walk_iomem_res_desc(start
, end
, flags
, desc
, arg
, func
);
414 EXPORT_SYMBOL_GPL(walk_iomem_res_desc
);
417 * This function calls the @func callback against all memory ranges of type
418 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
419 * Now, this function is only for System RAM, it deals with full ranges and
420 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
423 int walk_system_ram_res(u64 start
, u64 end
, void *arg
,
424 int (*func
)(struct resource
*, void *))
426 unsigned long flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
428 return __walk_iomem_res_desc(start
, end
, flags
, IORES_DESC_NONE
, arg
,
433 * This function calls the @func callback against all memory ranges, which
434 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
436 int walk_mem_res(u64 start
, u64 end
, void *arg
,
437 int (*func
)(struct resource
*, void *))
439 unsigned long flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
441 return __walk_iomem_res_desc(start
, end
, flags
, IORES_DESC_NONE
, arg
,
446 * This function calls the @func callback against all memory ranges of type
447 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
448 * It is to be used only for System RAM.
450 int walk_system_ram_range(unsigned long start_pfn
, unsigned long nr_pages
,
451 void *arg
, int (*func
)(unsigned long, unsigned long, void *))
453 resource_size_t start
, end
;
456 unsigned long pfn
, end_pfn
;
459 start
= (u64
) start_pfn
<< PAGE_SHIFT
;
460 end
= ((u64
)(start_pfn
+ nr_pages
) << PAGE_SHIFT
) - 1;
461 flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
462 while (start
< end
&&
463 !find_next_iomem_res(start
, end
, flags
, IORES_DESC_NONE
, &res
)) {
464 pfn
= PFN_UP(res
.start
);
465 end_pfn
= PFN_DOWN(res
.end
+ 1);
467 ret
= (*func
)(pfn
, end_pfn
- pfn
, arg
);
475 static int __is_ram(unsigned long pfn
, unsigned long nr_pages
, void *arg
)
481 * This generic page_is_ram() returns true if specified address is
482 * registered as System RAM in iomem_resource list.
484 int __weak
page_is_ram(unsigned long pfn
)
486 return walk_system_ram_range(pfn
, 1, NULL
, __is_ram
) == 1;
488 EXPORT_SYMBOL_GPL(page_is_ram
);
490 static int __region_intersects(struct resource
*parent
, resource_size_t start
,
491 size_t size
, unsigned long flags
,
495 int type
= 0; int other
= 0;
499 res
.end
= start
+ size
- 1;
501 for (p
= parent
->child
; p
; p
= p
->sibling
) {
502 bool is_type
= (((p
->flags
& flags
) == flags
) &&
503 ((desc
== IORES_DESC_NONE
) ||
506 if (resource_overlaps(p
, &res
))
507 is_type
? type
++ : other
++;
511 return REGION_DISJOINT
;
514 return REGION_INTERSECTS
;
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
,
544 read_lock(&resource_lock
);
545 ret
= __region_intersects(&iomem_resource
, start
, size
, flags
, desc
);
546 read_unlock(&resource_lock
);
550 EXPORT_SYMBOL_GPL(region_intersects
);
552 void __weak
arch_remove_reservations(struct resource
*avail
)
556 static resource_size_t
simple_align_resource(void *data
,
557 const struct resource
*avail
,
558 resource_size_t size
,
559 resource_size_t align
)
564 static void resource_clip(struct resource
*res
, resource_size_t min
,
567 if (res
->start
< min
)
574 * Find empty slot in the resource tree with the given range and
575 * alignment constraints
577 static int __find_resource(struct resource
*root
, struct resource
*old
,
578 struct resource
*new,
579 resource_size_t size
,
580 struct resource_constraint
*constraint
)
582 struct resource
*this = root
->child
;
583 struct resource tmp
= *new, avail
, alloc
;
585 tmp
.start
= root
->start
;
587 * Skip past an allocated resource that starts at 0, since the assignment
588 * of this->start - 1 to tmp->end below would cause an underflow.
590 if (this && this->start
== root
->start
) {
591 tmp
.start
= (this == old
) ? old
->start
: this->end
+ 1;
592 this = this->sibling
;
596 tmp
.end
= (this == old
) ? this->end
: this->start
- 1;
600 if (tmp
.end
< tmp
.start
)
603 resource_clip(&tmp
, constraint
->min
, constraint
->max
);
604 arch_remove_reservations(&tmp
);
606 /* Check for overflow after ALIGN() */
607 avail
.start
= ALIGN(tmp
.start
, constraint
->align
);
609 avail
.flags
= new->flags
& ~IORESOURCE_UNSET
;
610 if (avail
.start
>= tmp
.start
) {
611 alloc
.flags
= avail
.flags
;
612 alloc
.start
= constraint
->alignf(constraint
->alignf_data
, &avail
,
613 size
, constraint
->align
);
614 alloc
.end
= alloc
.start
+ size
- 1;
615 if (alloc
.start
<= alloc
.end
&&
616 resource_contains(&avail
, &alloc
)) {
617 new->start
= alloc
.start
;
618 new->end
= alloc
.end
;
623 next
: if (!this || this->end
== root
->end
)
627 tmp
.start
= this->end
+ 1;
628 this = this->sibling
;
634 * Find empty slot in the resource tree given range and alignment.
636 static int find_resource(struct resource
*root
, struct resource
*new,
637 resource_size_t size
,
638 struct resource_constraint
*constraint
)
640 return __find_resource(root
, NULL
, new, size
, constraint
);
644 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
645 * The resource will be relocated if the new size cannot be reallocated in the
648 * @root: root resource descriptor
649 * @old: resource descriptor desired by caller
650 * @newsize: new size of the resource descriptor
651 * @constraint: the size and alignment constraints to be met.
653 static int reallocate_resource(struct resource
*root
, struct resource
*old
,
654 resource_size_t newsize
,
655 struct resource_constraint
*constraint
)
658 struct resource
new = *old
;
659 struct resource
*conflict
;
661 write_lock(&resource_lock
);
663 if ((err
= __find_resource(root
, old
, &new, newsize
, constraint
)))
666 if (resource_contains(&new, old
)) {
667 old
->start
= new.start
;
677 if (resource_contains(old
, &new)) {
678 old
->start
= new.start
;
681 __release_resource(old
, true);
683 conflict
= __request_resource(root
, old
);
687 write_unlock(&resource_lock
);
693 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
694 * The resource will be reallocated with a new size if it was already allocated
695 * @root: root resource descriptor
696 * @new: resource descriptor desired by caller
697 * @size: requested resource region size
698 * @min: minimum boundary to allocate
699 * @max: maximum boundary to allocate
700 * @align: alignment requested, in bytes
701 * @alignf: alignment function, optional, called if not NULL
702 * @alignf_data: arbitrary data to pass to the @alignf function
704 int allocate_resource(struct resource
*root
, struct resource
*new,
705 resource_size_t size
, resource_size_t min
,
706 resource_size_t max
, resource_size_t align
,
707 resource_size_t (*alignf
)(void *,
708 const struct resource
*,
714 struct resource_constraint constraint
;
717 alignf
= simple_align_resource
;
719 constraint
.min
= min
;
720 constraint
.max
= max
;
721 constraint
.align
= align
;
722 constraint
.alignf
= alignf
;
723 constraint
.alignf_data
= alignf_data
;
726 /* resource is already allocated, try reallocating with
727 the new constraints */
728 return reallocate_resource(root
, new, size
, &constraint
);
731 write_lock(&resource_lock
);
732 err
= find_resource(root
, new, size
, &constraint
);
733 if (err
>= 0 && __request_resource(root
, new))
735 write_unlock(&resource_lock
);
739 EXPORT_SYMBOL(allocate_resource
);
742 * lookup_resource - find an existing resource by a resource start address
743 * @root: root resource descriptor
744 * @start: resource start address
746 * Returns a pointer to the resource if found, NULL otherwise
748 struct resource
*lookup_resource(struct resource
*root
, resource_size_t start
)
750 struct resource
*res
;
752 read_lock(&resource_lock
);
753 for (res
= root
->child
; res
; res
= res
->sibling
) {
754 if (res
->start
== start
)
757 read_unlock(&resource_lock
);
763 * Insert a resource into the resource tree. If successful, return NULL,
764 * otherwise return the conflicting resource (compare to __request_resource())
766 static struct resource
* __insert_resource(struct resource
*parent
, struct resource
*new)
768 struct resource
*first
, *next
;
770 for (;; parent
= first
) {
771 first
= __request_resource(parent
, new);
777 if (WARN_ON(first
== new)) /* duplicated insertion */
780 if ((first
->start
> new->start
) || (first
->end
< new->end
))
782 if ((first
->start
== new->start
) && (first
->end
== new->end
))
786 for (next
= first
; ; next
= next
->sibling
) {
787 /* Partial overlap? Bad, and unfixable */
788 if (next
->start
< new->start
|| next
->end
> new->end
)
792 if (next
->sibling
->start
> new->end
)
796 new->parent
= parent
;
797 new->sibling
= next
->sibling
;
800 next
->sibling
= NULL
;
801 for (next
= first
; next
; next
= next
->sibling
)
804 if (parent
->child
== first
) {
807 next
= parent
->child
;
808 while (next
->sibling
!= first
)
809 next
= next
->sibling
;
816 * insert_resource_conflict - Inserts resource in the resource tree
817 * @parent: parent of the new resource
818 * @new: new resource to insert
820 * Returns 0 on success, conflict resource if the resource can't be inserted.
822 * This function is equivalent to request_resource_conflict when no conflict
823 * happens. If a conflict happens, and the conflicting resources
824 * entirely fit within the range of the new resource, then the new
825 * resource is inserted and the conflicting resources become children of
828 * This function is intended for producers of resources, such as FW modules
831 struct resource
*insert_resource_conflict(struct resource
*parent
, struct resource
*new)
833 struct resource
*conflict
;
835 write_lock(&resource_lock
);
836 conflict
= __insert_resource(parent
, new);
837 write_unlock(&resource_lock
);
842 * insert_resource - Inserts a resource in the resource tree
843 * @parent: parent of the new resource
844 * @new: new resource to insert
846 * Returns 0 on success, -EBUSY if the resource can't be inserted.
848 * This function is intended for producers of resources, such as FW modules
851 int insert_resource(struct resource
*parent
, struct resource
*new)
853 struct resource
*conflict
;
855 conflict
= insert_resource_conflict(parent
, new);
856 return conflict
? -EBUSY
: 0;
858 EXPORT_SYMBOL_GPL(insert_resource
);
861 * insert_resource_expand_to_fit - Insert a resource into the resource tree
862 * @root: root resource descriptor
863 * @new: new resource to insert
865 * Insert a resource into the resource tree, possibly expanding it in order
866 * to make it encompass any conflicting resources.
868 void insert_resource_expand_to_fit(struct resource
*root
, struct resource
*new)
873 write_lock(&resource_lock
);
875 struct resource
*conflict
;
877 conflict
= __insert_resource(root
, new);
880 if (conflict
== root
)
883 /* Ok, expand resource to cover the conflict, then try again .. */
884 if (conflict
->start
< new->start
)
885 new->start
= conflict
->start
;
886 if (conflict
->end
> new->end
)
887 new->end
= conflict
->end
;
889 pr_info("Expanded resource %s due to conflict with %s\n", new->name
, conflict
->name
);
891 write_unlock(&resource_lock
);
894 * Not for general consumption, only early boot memory map parsing, PCI
895 * resource discovery, and late discovery of CXL resources are expected
896 * to use this interface. The former are built-in and only the latter,
899 EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit
, CXL
);
902 * remove_resource - Remove a resource in the resource tree
903 * @old: resource to remove
905 * Returns 0 on success, -EINVAL if the resource is not valid.
907 * This function removes a resource previously inserted by insert_resource()
908 * or insert_resource_conflict(), and moves the children (if any) up to
909 * where they were before. insert_resource() and insert_resource_conflict()
910 * insert a new resource, and move any conflicting resources down to the
911 * children of the new resource.
913 * insert_resource(), insert_resource_conflict() and remove_resource() are
914 * intended for producers of resources, such as FW modules and bus drivers.
916 int remove_resource(struct resource
*old
)
920 write_lock(&resource_lock
);
921 retval
= __release_resource(old
, false);
922 write_unlock(&resource_lock
);
925 EXPORT_SYMBOL_GPL(remove_resource
);
927 static int __adjust_resource(struct resource
*res
, resource_size_t start
,
928 resource_size_t size
)
930 struct resource
*tmp
, *parent
= res
->parent
;
931 resource_size_t end
= start
+ size
- 1;
937 if ((start
< parent
->start
) || (end
> parent
->end
))
940 if (res
->sibling
&& (res
->sibling
->start
<= end
))
945 while (tmp
->sibling
!= res
)
947 if (start
<= tmp
->end
)
952 for (tmp
= res
->child
; tmp
; tmp
= tmp
->sibling
)
953 if ((tmp
->start
< start
) || (tmp
->end
> end
))
965 * adjust_resource - modify a resource's start and size
966 * @res: resource to modify
967 * @start: new start value
970 * Given an existing resource, change its start and size to match the
971 * arguments. Returns 0 on success, -EBUSY if it can't fit.
972 * Existing children of the resource are assumed to be immutable.
974 int adjust_resource(struct resource
*res
, resource_size_t start
,
975 resource_size_t size
)
979 write_lock(&resource_lock
);
980 result
= __adjust_resource(res
, start
, size
);
981 write_unlock(&resource_lock
);
984 EXPORT_SYMBOL(adjust_resource
);
987 __reserve_region_with_split(struct resource
*root
, resource_size_t start
,
988 resource_size_t end
, const char *name
)
990 struct resource
*parent
= root
;
991 struct resource
*conflict
;
992 struct resource
*res
= alloc_resource(GFP_ATOMIC
);
993 struct resource
*next_res
= NULL
;
994 int type
= resource_type(root
);
1002 res
->flags
= type
| IORESOURCE_BUSY
;
1003 res
->desc
= IORES_DESC_NONE
;
1007 conflict
= __request_resource(parent
, res
);
1016 /* conflict covered whole area */
1017 if (conflict
->start
<= res
->start
&&
1018 conflict
->end
>= res
->end
) {
1024 /* failed, split and try again */
1025 if (conflict
->start
> res
->start
) {
1027 res
->end
= conflict
->start
- 1;
1028 if (conflict
->end
< end
) {
1029 next_res
= alloc_resource(GFP_ATOMIC
);
1034 next_res
->name
= name
;
1035 next_res
->start
= conflict
->end
+ 1;
1036 next_res
->end
= end
;
1037 next_res
->flags
= type
| IORESOURCE_BUSY
;
1038 next_res
->desc
= IORES_DESC_NONE
;
1041 res
->start
= conflict
->end
+ 1;
1048 reserve_region_with_split(struct resource
*root
, resource_size_t start
,
1049 resource_size_t end
, const char *name
)
1053 write_lock(&resource_lock
);
1054 if (root
->start
> start
|| root
->end
< end
) {
1055 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1056 (unsigned long long)start
, (unsigned long long)end
,
1058 if (start
> root
->end
|| end
< root
->start
)
1061 if (end
> root
->end
)
1063 if (start
< root
->start
)
1064 start
= root
->start
;
1065 pr_err("fixing request to [0x%llx-0x%llx]\n",
1066 (unsigned long long)start
,
1067 (unsigned long long)end
);
1072 __reserve_region_with_split(root
, start
, end
, name
);
1073 write_unlock(&resource_lock
);
1077 * resource_alignment - calculate resource's alignment
1078 * @res: resource pointer
1080 * Returns alignment on success, 0 (invalid alignment) on failure.
1082 resource_size_t
resource_alignment(struct resource
*res
)
1084 switch (res
->flags
& (IORESOURCE_SIZEALIGN
| IORESOURCE_STARTALIGN
)) {
1085 case IORESOURCE_SIZEALIGN
:
1086 return resource_size(res
);
1087 case IORESOURCE_STARTALIGN
:
1095 * This is compatibility stuff for IO resources.
1097 * Note how this, unlike the above, knows about
1098 * the IO flag meanings (busy etc).
1100 * request_region creates a new busy region.
1102 * release_region releases a matching busy region.
1105 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait
);
1107 static struct inode
*iomem_inode
;
1109 #ifdef CONFIG_IO_STRICT_DEVMEM
1110 static void revoke_iomem(struct resource
*res
)
1112 /* pairs with smp_store_release() in iomem_init_inode() */
1113 struct inode
*inode
= smp_load_acquire(&iomem_inode
);
1116 * Check that the initialization has completed. Losing the race
1117 * is ok because it means drivers are claiming resources before
1118 * the fs_initcall level of init and prevent iomem_get_mapping users
1119 * from establishing mappings.
1125 * The expectation is that the driver has successfully marked
1126 * the resource busy by this point, so devmem_is_allowed()
1127 * should start returning false, however for performance this
1128 * does not iterate the entire resource range.
1130 if (devmem_is_allowed(PHYS_PFN(res
->start
)) &&
1131 devmem_is_allowed(PHYS_PFN(res
->end
))) {
1133 * *cringe* iomem=relaxed says "go ahead, what's the
1134 * worst that can happen?"
1139 unmap_mapping_range(inode
->i_mapping
, res
->start
, resource_size(res
), 1);
1142 static void revoke_iomem(struct resource
*res
) {}
1145 struct address_space
*iomem_get_mapping(void)
1148 * This function is only called from file open paths, hence guaranteed
1149 * that fs_initcalls have completed and no need to check for NULL. But
1150 * since revoke_iomem can be called before the initcall we still need
1151 * the barrier to appease checkers.
1153 return smp_load_acquire(&iomem_inode
)->i_mapping
;
1156 static int __request_region_locked(struct resource
*res
, struct resource
*parent
,
1157 resource_size_t start
, resource_size_t n
,
1158 const char *name
, int flags
)
1160 DECLARE_WAITQUEUE(wait
, current
);
1164 res
->end
= start
+ n
- 1;
1167 struct resource
*conflict
;
1169 res
->flags
= resource_type(parent
) | resource_ext_type(parent
);
1170 res
->flags
|= IORESOURCE_BUSY
| flags
;
1171 res
->desc
= parent
->desc
;
1173 conflict
= __request_resource(parent
, res
);
1177 * mm/hmm.c reserves physical addresses which then
1178 * become unavailable to other users. Conflicts are
1179 * not expected. Warn to aid debugging if encountered.
1181 if (conflict
->desc
== IORES_DESC_DEVICE_PRIVATE_MEMORY
) {
1182 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1183 conflict
->name
, conflict
, res
);
1185 if (conflict
!= parent
) {
1186 if (!(conflict
->flags
& IORESOURCE_BUSY
)) {
1191 if (conflict
->flags
& flags
& IORESOURCE_MUXED
) {
1192 add_wait_queue(&muxed_resource_wait
, &wait
);
1193 write_unlock(&resource_lock
);
1194 set_current_state(TASK_UNINTERRUPTIBLE
);
1196 remove_wait_queue(&muxed_resource_wait
, &wait
);
1197 write_lock(&resource_lock
);
1200 /* Uhhuh, that didn't work out.. */
1208 * __request_region - create a new busy resource region
1209 * @parent: parent resource descriptor
1210 * @start: resource start address
1211 * @n: resource region size
1212 * @name: reserving caller's ID string
1213 * @flags: IO resource flags
1215 struct resource
*__request_region(struct resource
*parent
,
1216 resource_size_t start
, resource_size_t n
,
1217 const char *name
, int flags
)
1219 struct resource
*res
= alloc_resource(GFP_KERNEL
);
1225 write_lock(&resource_lock
);
1226 ret
= __request_region_locked(res
, parent
, start
, n
, name
, flags
);
1227 write_unlock(&resource_lock
);
1234 if (parent
== &iomem_resource
)
1239 EXPORT_SYMBOL(__request_region
);
1242 * __release_region - release a previously reserved resource region
1243 * @parent: parent resource descriptor
1244 * @start: resource start address
1245 * @n: resource region size
1247 * The described resource region must match a currently busy region.
1249 void __release_region(struct resource
*parent
, resource_size_t start
,
1252 struct resource
**p
;
1253 resource_size_t end
;
1256 end
= start
+ n
- 1;
1258 write_lock(&resource_lock
);
1261 struct resource
*res
= *p
;
1265 if (res
->start
<= start
&& res
->end
>= end
) {
1266 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1270 if (res
->start
!= start
|| res
->end
!= end
)
1273 write_unlock(&resource_lock
);
1274 if (res
->flags
& IORESOURCE_MUXED
)
1275 wake_up(&muxed_resource_wait
);
1282 write_unlock(&resource_lock
);
1284 pr_warn("Trying to free nonexistent resource <%pa-%pa>\n", &start
, &end
);
1286 EXPORT_SYMBOL(__release_region
);
1288 #ifdef CONFIG_MEMORY_HOTREMOVE
1290 * release_mem_region_adjustable - release a previously reserved memory region
1291 * @start: resource start address
1292 * @size: resource region size
1294 * This interface is intended for memory hot-delete. The requested region
1295 * is released from a currently busy memory resource. The requested region
1296 * must either match exactly or fit into a single busy resource entry. In
1297 * the latter case, the remaining resource is adjusted accordingly.
1298 * Existing children of the busy memory resource must be immutable in the
1302 * - Additional release conditions, such as overlapping region, can be
1303 * supported after they are confirmed as valid cases.
1304 * - When a busy memory resource gets split into two entries, the code
1305 * assumes that all children remain in the lower address entry for
1306 * simplicity. Enhance this logic when necessary.
1308 void release_mem_region_adjustable(resource_size_t start
, resource_size_t size
)
1310 struct resource
*parent
= &iomem_resource
;
1311 struct resource
*new_res
= NULL
;
1312 bool alloc_nofail
= false;
1313 struct resource
**p
;
1314 struct resource
*res
;
1315 resource_size_t end
;
1317 end
= start
+ size
- 1;
1318 if (WARN_ON_ONCE((start
< parent
->start
) || (end
> parent
->end
)))
1322 * We free up quite a lot of memory on memory hotunplug (esp., memap),
1323 * just before releasing the region. This is highly unlikely to
1324 * fail - let's play save and make it never fail as the caller cannot
1325 * perform any error handling (e.g., trying to re-add memory will fail
1329 new_res
= alloc_resource(GFP_KERNEL
| (alloc_nofail
? __GFP_NOFAIL
: 0));
1332 write_lock(&resource_lock
);
1334 while ((res
= *p
)) {
1335 if (res
->start
>= end
)
1338 /* look for the next resource if it does not fit into */
1339 if (res
->start
> start
|| res
->end
< end
) {
1344 if (!(res
->flags
& IORESOURCE_MEM
))
1347 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1352 /* found the target resource; let's adjust accordingly */
1353 if (res
->start
== start
&& res
->end
== end
) {
1354 /* free the whole entry */
1357 } else if (res
->start
== start
&& res
->end
!= end
) {
1358 /* adjust the start */
1359 WARN_ON_ONCE(__adjust_resource(res
, end
+ 1,
1361 } else if (res
->start
!= start
&& res
->end
== end
) {
1362 /* adjust the end */
1363 WARN_ON_ONCE(__adjust_resource(res
, res
->start
,
1364 start
- res
->start
));
1366 /* split into two entries - we need a new resource */
1368 new_res
= alloc_resource(GFP_ATOMIC
);
1370 alloc_nofail
= true;
1371 write_unlock(&resource_lock
);
1375 new_res
->name
= res
->name
;
1376 new_res
->start
= end
+ 1;
1377 new_res
->end
= res
->end
;
1378 new_res
->flags
= res
->flags
;
1379 new_res
->desc
= res
->desc
;
1380 new_res
->parent
= res
->parent
;
1381 new_res
->sibling
= res
->sibling
;
1382 new_res
->child
= NULL
;
1384 if (WARN_ON_ONCE(__adjust_resource(res
, res
->start
,
1385 start
- res
->start
)))
1387 res
->sibling
= new_res
;
1394 write_unlock(&resource_lock
);
1395 free_resource(new_res
);
1397 #endif /* CONFIG_MEMORY_HOTREMOVE */
1399 #ifdef CONFIG_MEMORY_HOTPLUG
1400 static bool system_ram_resources_mergeable(struct resource
*r1
,
1401 struct resource
*r2
)
1403 /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1404 return r1
->flags
== r2
->flags
&& r1
->end
+ 1 == r2
->start
&&
1405 r1
->name
== r2
->name
&& r1
->desc
== r2
->desc
&&
1406 !r1
->child
&& !r2
->child
;
1410 * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1411 * merge it with adjacent, mergeable resources
1412 * @res: resource descriptor
1414 * This interface is intended for memory hotplug, whereby lots of contiguous
1415 * system ram resources are added (e.g., via add_memory*()) by a driver, and
1416 * the actual resource boundaries are not of interest (e.g., it might be
1417 * relevant for DIMMs). Only resources that are marked mergeable, that have the
1418 * same parent, and that don't have any children are considered. All mergeable
1419 * resources must be immutable during the request.
1422 * - The caller has to make sure that no pointers to resources that are
1423 * marked mergeable are used anymore after this call - the resource might
1424 * be freed and the pointer might be stale!
1425 * - release_mem_region_adjustable() will split on demand on memory hotunplug
1427 void merge_system_ram_resource(struct resource
*res
)
1429 const unsigned long flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
1430 struct resource
*cur
;
1432 if (WARN_ON_ONCE((res
->flags
& flags
) != flags
))
1435 write_lock(&resource_lock
);
1436 res
->flags
|= IORESOURCE_SYSRAM_MERGEABLE
;
1438 /* Try to merge with next item in the list. */
1440 if (cur
&& system_ram_resources_mergeable(res
, cur
)) {
1441 res
->end
= cur
->end
;
1442 res
->sibling
= cur
->sibling
;
1446 /* Try to merge with previous item in the list. */
1447 cur
= res
->parent
->child
;
1448 while (cur
&& cur
->sibling
!= res
)
1450 if (cur
&& system_ram_resources_mergeable(cur
, res
)) {
1451 cur
->end
= res
->end
;
1452 cur
->sibling
= res
->sibling
;
1455 write_unlock(&resource_lock
);
1457 #endif /* CONFIG_MEMORY_HOTPLUG */
1460 * Managed region resource
1462 static void devm_resource_release(struct device
*dev
, void *ptr
)
1464 struct resource
**r
= ptr
;
1466 release_resource(*r
);
1470 * devm_request_resource() - request and reserve an I/O or memory resource
1471 * @dev: device for which to request the resource
1472 * @root: root of the resource tree from which to request the resource
1473 * @new: descriptor of the resource to request
1475 * This is a device-managed version of request_resource(). There is usually
1476 * no need to release resources requested by this function explicitly since
1477 * that will be taken care of when the device is unbound from its driver.
1478 * If for some reason the resource needs to be released explicitly, because
1479 * of ordering issues for example, drivers must call devm_release_resource()
1480 * rather than the regular release_resource().
1482 * When a conflict is detected between any existing resources and the newly
1483 * requested resource, an error message will be printed.
1485 * Returns 0 on success or a negative error code on failure.
1487 int devm_request_resource(struct device
*dev
, struct resource
*root
,
1488 struct resource
*new)
1490 struct resource
*conflict
, **ptr
;
1492 ptr
= devres_alloc(devm_resource_release
, sizeof(*ptr
), GFP_KERNEL
);
1498 conflict
= request_resource_conflict(root
, new);
1500 dev_err(dev
, "resource collision: %pR conflicts with %s %pR\n",
1501 new, conflict
->name
, conflict
);
1506 devres_add(dev
, ptr
);
1509 EXPORT_SYMBOL(devm_request_resource
);
1511 static int devm_resource_match(struct device
*dev
, void *res
, void *data
)
1513 struct resource
**ptr
= res
;
1515 return *ptr
== data
;
1519 * devm_release_resource() - release a previously requested resource
1520 * @dev: device for which to release the resource
1521 * @new: descriptor of the resource to release
1523 * Releases a resource previously requested using devm_request_resource().
1525 void devm_release_resource(struct device
*dev
, struct resource
*new)
1527 WARN_ON(devres_release(dev
, devm_resource_release
, devm_resource_match
,
1530 EXPORT_SYMBOL(devm_release_resource
);
1532 struct region_devres
{
1533 struct resource
*parent
;
1534 resource_size_t start
;
1538 static void devm_region_release(struct device
*dev
, void *res
)
1540 struct region_devres
*this = res
;
1542 __release_region(this->parent
, this->start
, this->n
);
1545 static int devm_region_match(struct device
*dev
, void *res
, void *match_data
)
1547 struct region_devres
*this = res
, *match
= match_data
;
1549 return this->parent
== match
->parent
&&
1550 this->start
== match
->start
&& this->n
== match
->n
;
1554 __devm_request_region(struct device
*dev
, struct resource
*parent
,
1555 resource_size_t start
, resource_size_t n
, const char *name
)
1557 struct region_devres
*dr
= NULL
;
1558 struct resource
*res
;
1560 dr
= devres_alloc(devm_region_release
, sizeof(struct region_devres
),
1565 dr
->parent
= parent
;
1569 res
= __request_region(parent
, start
, n
, name
, 0);
1571 devres_add(dev
, dr
);
1577 EXPORT_SYMBOL(__devm_request_region
);
1579 void __devm_release_region(struct device
*dev
, struct resource
*parent
,
1580 resource_size_t start
, resource_size_t n
)
1582 struct region_devres match_data
= { parent
, start
, n
};
1584 __release_region(parent
, start
, n
);
1585 WARN_ON(devres_destroy(dev
, devm_region_release
, devm_region_match
,
1588 EXPORT_SYMBOL(__devm_release_region
);
1591 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1593 #define MAXRESERVE 4
1594 static int __init
reserve_setup(char *str
)
1596 static int reserved
;
1597 static struct resource reserve
[MAXRESERVE
];
1600 unsigned int io_start
, io_num
;
1602 struct resource
*parent
;
1604 if (get_option(&str
, &io_start
) != 2)
1606 if (get_option(&str
, &io_num
) == 0)
1608 if (x
< MAXRESERVE
) {
1609 struct resource
*res
= reserve
+ x
;
1612 * If the region starts below 0x10000, we assume it's
1613 * I/O port space; otherwise assume it's memory.
1615 if (io_start
< 0x10000) {
1616 res
->flags
= IORESOURCE_IO
;
1617 parent
= &ioport_resource
;
1619 res
->flags
= IORESOURCE_MEM
;
1620 parent
= &iomem_resource
;
1622 res
->name
= "reserved";
1623 res
->start
= io_start
;
1624 res
->end
= io_start
+ io_num
- 1;
1625 res
->flags
|= IORESOURCE_BUSY
;
1626 res
->desc
= IORES_DESC_NONE
;
1628 if (request_resource(parent
, res
) == 0)
1634 __setup("reserve=", reserve_setup
);
1637 * Check if the requested addr and size spans more than any slot in the
1638 * iomem resource tree.
1640 int iomem_map_sanity_check(resource_size_t addr
, unsigned long size
)
1642 resource_size_t end
= addr
+ size
- 1;
1646 read_lock(&resource_lock
);
1647 for_each_resource(&iomem_resource
, p
, false) {
1649 * We can probably skip the resources without
1650 * IORESOURCE_IO attribute?
1656 if (PFN_DOWN(p
->start
) <= PFN_DOWN(addr
) &&
1657 PFN_DOWN(p
->end
) >= PFN_DOWN(end
))
1660 * if a resource is "BUSY", it's not a hardware resource
1661 * but a driver mapping of such a resource; we don't want
1662 * to warn for those; some drivers legitimately map only
1663 * partial hardware resources. (example: vesafb)
1665 if (p
->flags
& IORESOURCE_BUSY
)
1668 pr_warn("resource sanity check: requesting [mem %pa-%pa], which spans more than %s %pR\n",
1669 &addr
, &end
, p
->name
, p
);
1673 read_unlock(&resource_lock
);
1678 #ifdef CONFIG_STRICT_DEVMEM
1679 static int strict_iomem_checks
= 1;
1681 static int strict_iomem_checks
;
1685 * Check if an address is exclusive to the kernel and must not be mapped to
1686 * user space, for example, via /dev/mem.
1688 * Returns true if exclusive to the kernel, otherwise returns false.
1690 bool resource_is_exclusive(struct resource
*root
, u64 addr
, resource_size_t size
)
1692 const unsigned int exclusive_system_ram
= IORESOURCE_SYSTEM_RAM
|
1693 IORESOURCE_EXCLUSIVE
;
1694 bool skip_children
= false, err
= false;
1697 read_lock(&resource_lock
);
1698 for_each_resource(root
, p
, skip_children
) {
1699 if (p
->start
>= addr
+ size
)
1701 if (p
->end
< addr
) {
1702 skip_children
= true;
1705 skip_children
= false;
1708 * IORESOURCE_SYSTEM_RAM resources are exclusive if
1709 * IORESOURCE_EXCLUSIVE is set, even if they
1710 * are not busy and even if "iomem=relaxed" is set. The
1711 * responsible driver dynamically adds/removes system RAM within
1712 * such an area and uncontrolled access is dangerous.
1714 if ((p
->flags
& exclusive_system_ram
) == exclusive_system_ram
) {
1720 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1721 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1724 if (!strict_iomem_checks
|| !(p
->flags
& IORESOURCE_BUSY
))
1726 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM
)
1727 || p
->flags
& IORESOURCE_EXCLUSIVE
) {
1732 read_unlock(&resource_lock
);
1737 bool iomem_is_exclusive(u64 addr
)
1739 return resource_is_exclusive(&iomem_resource
, addr
& PAGE_MASK
,
1743 struct resource_entry
*resource_list_create_entry(struct resource
*res
,
1746 struct resource_entry
*entry
;
1748 entry
= kzalloc(sizeof(*entry
) + extra_size
, GFP_KERNEL
);
1750 INIT_LIST_HEAD(&entry
->node
);
1751 entry
->res
= res
? res
: &entry
->__res
;
1756 EXPORT_SYMBOL(resource_list_create_entry
);
1758 void resource_list_free(struct list_head
*head
)
1760 struct resource_entry
*entry
, *tmp
;
1762 list_for_each_entry_safe(entry
, tmp
, head
, node
)
1763 resource_list_destroy_entry(entry
);
1765 EXPORT_SYMBOL(resource_list_free
);
1767 #ifdef CONFIG_GET_FREE_REGION
1768 #define GFR_DESCENDING (1UL << 0)
1769 #define GFR_REQUEST_REGION (1UL << 1)
1770 #define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT)
1772 static resource_size_t
gfr_start(struct resource
*base
, resource_size_t size
,
1773 resource_size_t align
, unsigned long flags
)
1775 if (flags
& GFR_DESCENDING
) {
1776 resource_size_t end
;
1778 end
= min_t(resource_size_t
, base
->end
,
1779 (1ULL << MAX_PHYSMEM_BITS
) - 1);
1780 return end
- size
+ 1;
1783 return ALIGN(base
->start
, align
);
1786 static bool gfr_continue(struct resource
*base
, resource_size_t addr
,
1787 resource_size_t size
, unsigned long flags
)
1789 if (flags
& GFR_DESCENDING
)
1790 return addr
> size
&& addr
>= base
->start
;
1792 * In the ascend case be careful that the last increment by
1793 * @size did not wrap 0.
1795 return addr
> addr
- size
&&
1796 addr
<= min_t(resource_size_t
, base
->end
,
1797 (1ULL << MAX_PHYSMEM_BITS
) - 1);
1800 static resource_size_t
gfr_next(resource_size_t addr
, resource_size_t size
,
1801 unsigned long flags
)
1803 if (flags
& GFR_DESCENDING
)
1808 static void remove_free_mem_region(void *_res
)
1810 struct resource
*res
= _res
;
1813 remove_resource(res
);
1817 static struct resource
*
1818 get_free_mem_region(struct device
*dev
, struct resource
*base
,
1819 resource_size_t size
, const unsigned long align
,
1820 const char *name
, const unsigned long desc
,
1821 const unsigned long flags
)
1823 resource_size_t addr
;
1824 struct resource
*res
;
1825 struct region_devres
*dr
= NULL
;
1827 size
= ALIGN(size
, align
);
1829 res
= alloc_resource(GFP_KERNEL
);
1831 return ERR_PTR(-ENOMEM
);
1833 if (dev
&& (flags
& GFR_REQUEST_REGION
)) {
1834 dr
= devres_alloc(devm_region_release
,
1835 sizeof(struct region_devres
), GFP_KERNEL
);
1838 return ERR_PTR(-ENOMEM
);
1841 if (devm_add_action_or_reset(dev
, remove_free_mem_region
, res
))
1842 return ERR_PTR(-ENOMEM
);
1845 write_lock(&resource_lock
);
1846 for (addr
= gfr_start(base
, size
, align
, flags
);
1847 gfr_continue(base
, addr
, size
, flags
);
1848 addr
= gfr_next(addr
, size
, flags
)) {
1849 if (__region_intersects(base
, addr
, size
, 0, IORES_DESC_NONE
) !=
1853 if (flags
& GFR_REQUEST_REGION
) {
1854 if (__request_region_locked(res
, &iomem_resource
, addr
,
1859 dr
->parent
= &iomem_resource
;
1862 devres_add(dev
, dr
);
1866 write_unlock(&resource_lock
);
1870 * A driver is claiming this region so revoke any
1876 res
->end
= addr
+ size
- 1;
1879 res
->flags
= IORESOURCE_MEM
;
1882 * Only succeed if the resource hosts an exclusive
1883 * range after the insert
1885 if (__insert_resource(base
, res
) || res
->child
)
1888 write_unlock(&resource_lock
);
1893 write_unlock(&resource_lock
);
1895 if (flags
& GFR_REQUEST_REGION
) {
1899 devm_release_action(dev
, remove_free_mem_region
, res
);
1901 return ERR_PTR(-ERANGE
);
1905 * devm_request_free_mem_region - find free region for device private memory
1907 * @dev: device struct to bind the resource to
1908 * @size: size in bytes of the device memory to add
1909 * @base: resource tree to look in
1911 * This function tries to find an empty range of physical address big enough to
1912 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1913 * memory, which in turn allocates struct pages.
1915 struct resource
*devm_request_free_mem_region(struct device
*dev
,
1916 struct resource
*base
, unsigned long size
)
1918 unsigned long flags
= GFR_DESCENDING
| GFR_REQUEST_REGION
;
1920 return get_free_mem_region(dev
, base
, size
, GFR_DEFAULT_ALIGN
,
1922 IORES_DESC_DEVICE_PRIVATE_MEMORY
, flags
);
1924 EXPORT_SYMBOL_GPL(devm_request_free_mem_region
);
1926 struct resource
*request_free_mem_region(struct resource
*base
,
1927 unsigned long size
, const char *name
)
1929 unsigned long flags
= GFR_DESCENDING
| GFR_REQUEST_REGION
;
1931 return get_free_mem_region(NULL
, base
, size
, GFR_DEFAULT_ALIGN
, name
,
1932 IORES_DESC_DEVICE_PRIVATE_MEMORY
, flags
);
1934 EXPORT_SYMBOL_GPL(request_free_mem_region
);
1937 * alloc_free_mem_region - find a free region relative to @base
1938 * @base: resource that will parent the new resource
1939 * @size: size in bytes of memory to allocate from @base
1940 * @align: alignment requirements for the allocation
1941 * @name: resource name
1943 * Buses like CXL, that can dynamically instantiate new memory regions,
1944 * need a method to allocate physical address space for those regions.
1945 * Allocate and insert a new resource to cover a free, unclaimed by a
1946 * descendant of @base, range in the span of @base.
1948 struct resource
*alloc_free_mem_region(struct resource
*base
,
1949 unsigned long size
, unsigned long align
,
1952 /* Default of ascending direction and insert resource */
1953 unsigned long flags
= 0;
1955 return get_free_mem_region(NULL
, base
, size
, align
, name
,
1956 IORES_DESC_NONE
, flags
);
1958 EXPORT_SYMBOL_NS_GPL(alloc_free_mem_region
, CXL
);
1959 #endif /* CONFIG_GET_FREE_REGION */
1961 static int __init
strict_iomem(char *str
)
1963 if (strstr(str
, "relaxed"))
1964 strict_iomem_checks
= 0;
1965 if (strstr(str
, "strict"))
1966 strict_iomem_checks
= 1;
1970 static int iomem_fs_init_fs_context(struct fs_context
*fc
)
1972 return init_pseudo(fc
, DEVMEM_MAGIC
) ? 0 : -ENOMEM
;
1975 static struct file_system_type iomem_fs_type
= {
1977 .owner
= THIS_MODULE
,
1978 .init_fs_context
= iomem_fs_init_fs_context
,
1979 .kill_sb
= kill_anon_super
,
1982 static int __init
iomem_init_inode(void)
1984 static struct vfsmount
*iomem_vfs_mount
;
1985 static int iomem_fs_cnt
;
1986 struct inode
*inode
;
1989 rc
= simple_pin_fs(&iomem_fs_type
, &iomem_vfs_mount
, &iomem_fs_cnt
);
1991 pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc
);
1995 inode
= alloc_anon_inode(iomem_vfs_mount
->mnt_sb
);
1996 if (IS_ERR(inode
)) {
1997 rc
= PTR_ERR(inode
);
1998 pr_err("Cannot allocate inode for iomem: %d\n", rc
);
1999 simple_release_fs(&iomem_vfs_mount
, &iomem_fs_cnt
);
2004 * Publish iomem revocation inode initialized.
2005 * Pairs with smp_load_acquire() in revoke_iomem().
2007 smp_store_release(&iomem_inode
, inode
);
2012 fs_initcall(iomem_init_inode
);
2014 __setup("iomem=", strict_iomem
);