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
)
63 while (!p
->sibling
&& p
->parent
)
68 static struct resource
*next_resource_skip_children(struct resource
*p
)
70 while (!p
->sibling
&& p
->parent
)
75 #define for_each_resource(_root, _p, _skip_children) \
76 for ((_p) = (_root)->child; (_p); \
77 (_p) = (_skip_children) ? next_resource_skip_children(_p) : \
80 static void *r_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
82 struct resource
*p
= v
;
84 return (void *)next_resource(p
);
89 enum { MAX_IORES_LEVEL
= 5 };
91 static void *r_start(struct seq_file
*m
, loff_t
*pos
)
92 __acquires(resource_lock
)
94 struct resource
*p
= pde_data(file_inode(m
->file
));
96 read_lock(&resource_lock
);
97 for (p
= p
->child
; p
&& l
< *pos
; p
= r_next(m
, p
, &l
))
102 static void r_stop(struct seq_file
*m
, void *v
)
103 __releases(resource_lock
)
105 read_unlock(&resource_lock
);
108 static int r_show(struct seq_file
*m
, void *v
)
110 struct resource
*root
= pde_data(file_inode(m
->file
));
111 struct resource
*r
= v
, *p
;
112 unsigned long long start
, end
;
113 int width
= root
->end
< 0x10000 ? 4 : 8;
116 for (depth
= 0, p
= r
; depth
< MAX_IORES_LEVEL
; depth
++, p
= p
->parent
)
117 if (p
->parent
== root
)
120 if (file_ns_capable(m
->file
, &init_user_ns
, CAP_SYS_ADMIN
)) {
127 seq_printf(m
, "%*s%0*llx-%0*llx : %s\n",
131 r
->name
? r
->name
: "<BAD>");
135 static const struct seq_operations resource_op
= {
142 static int __init
ioresources_init(void)
144 proc_create_seq_data("ioports", 0, NULL
, &resource_op
,
146 proc_create_seq_data("iomem", 0, NULL
, &resource_op
, &iomem_resource
);
149 __initcall(ioresources_init
);
151 #endif /* CONFIG_PROC_FS */
153 static void free_resource(struct resource
*res
)
156 * If the resource was allocated using memblock early during boot
157 * we'll leak it here: we can only return full pages back to the
158 * buddy and trying to be smart and reusing them eventually in
159 * alloc_resource() overcomplicates resource handling.
161 if (res
&& PageSlab(virt_to_head_page(res
)))
165 static struct resource
*alloc_resource(gfp_t flags
)
167 return kzalloc(sizeof(struct resource
), flags
);
170 /* Return the conflict entry if you can't request it */
171 static struct resource
* __request_resource(struct resource
*root
, struct resource
*new)
173 resource_size_t start
= new->start
;
174 resource_size_t end
= new->end
;
175 struct resource
*tmp
, **p
;
179 if (start
< root
->start
)
186 if (!tmp
|| tmp
->start
> end
) {
193 if (tmp
->end
< start
)
199 static int __release_resource(struct resource
*old
, bool release_child
)
201 struct resource
*tmp
, **p
, *chd
;
203 p
= &old
->parent
->child
;
209 if (release_child
|| !(tmp
->child
)) {
212 for (chd
= tmp
->child
;; chd
= chd
->sibling
) {
213 chd
->parent
= tmp
->parent
;
218 chd
->sibling
= tmp
->sibling
;
228 static void __release_child_resources(struct resource
*r
)
230 struct resource
*tmp
, *p
;
231 resource_size_t size
;
241 __release_child_resources(tmp
);
243 printk(KERN_DEBUG
"release child resource %pR\n", tmp
);
244 /* need to restore size, and keep flags */
245 size
= resource_size(tmp
);
251 void release_child_resources(struct resource
*r
)
253 write_lock(&resource_lock
);
254 __release_child_resources(r
);
255 write_unlock(&resource_lock
);
259 * request_resource_conflict - request and reserve an I/O or memory resource
260 * @root: root resource descriptor
261 * @new: resource descriptor desired by caller
263 * Returns 0 for success, conflict resource on error.
265 struct resource
*request_resource_conflict(struct resource
*root
, struct resource
*new)
267 struct resource
*conflict
;
269 write_lock(&resource_lock
);
270 conflict
= __request_resource(root
, new);
271 write_unlock(&resource_lock
);
276 * request_resource - request and reserve an I/O or memory resource
277 * @root: root resource descriptor
278 * @new: resource descriptor desired by caller
280 * Returns 0 for success, negative error code on error.
282 int request_resource(struct resource
*root
, struct resource
*new)
284 struct resource
*conflict
;
286 conflict
= request_resource_conflict(root
, new);
287 return conflict
? -EBUSY
: 0;
290 EXPORT_SYMBOL(request_resource
);
293 * release_resource - release a previously reserved resource
294 * @old: resource pointer
296 int release_resource(struct resource
*old
)
300 write_lock(&resource_lock
);
301 retval
= __release_resource(old
, true);
302 write_unlock(&resource_lock
);
306 EXPORT_SYMBOL(release_resource
);
309 * find_next_iomem_res - Finds the lowest iomem resource that covers part of
312 * If a resource is found, returns 0 and @*res is overwritten with the part
313 * of the resource that's within [@start..@end]; if none is found, returns
314 * -ENODEV. Returns -EINVAL for invalid parameters.
316 * @start: start address of the resource searched for
317 * @end: end address of same resource
318 * @flags: flags which the resource must have
319 * @desc: descriptor the resource must have
320 * @res: return ptr, if resource found
322 * The caller must specify @start, @end, @flags, and @desc
323 * (which may be IORES_DESC_NONE).
325 static int find_next_iomem_res(resource_size_t start
, resource_size_t end
,
326 unsigned long flags
, unsigned long desc
,
327 struct resource
*res
)
337 read_lock(&resource_lock
);
339 for (p
= iomem_resource
.child
; p
; p
= next_resource(p
)) {
340 /* If we passed the resource we are looking for, stop */
341 if (p
->start
> end
) {
346 /* Skip until we find a range that matches what we look for */
350 if ((p
->flags
& flags
) != flags
)
352 if ((desc
!= IORES_DESC_NONE
) && (desc
!= p
->desc
))
355 /* Found a match, break */
361 *res
= (struct resource
) {
362 .start
= max(start
, p
->start
),
363 .end
= min(end
, p
->end
),
370 read_unlock(&resource_lock
);
371 return p
? 0 : -ENODEV
;
374 static int __walk_iomem_res_desc(resource_size_t start
, resource_size_t end
,
375 unsigned long flags
, unsigned long desc
,
377 int (*func
)(struct resource
*, void *))
382 while (start
< end
&&
383 !find_next_iomem_res(start
, end
, flags
, desc
, &res
)) {
384 ret
= (*func
)(&res
, arg
);
395 * walk_iomem_res_desc - Walks through iomem resources and calls func()
396 * with matching resource ranges.
398 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
399 * @flags: I/O resource flags
402 * @arg: function argument for the callback @func
403 * @func: callback function that is called for each qualifying resource area
405 * All the memory ranges which overlap start,end and also match flags and
406 * desc are valid candidates.
408 * NOTE: For a new descriptor search, define a new IORES_DESC in
409 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
411 int walk_iomem_res_desc(unsigned long desc
, unsigned long flags
, u64 start
,
412 u64 end
, void *arg
, int (*func
)(struct resource
*, void *))
414 return __walk_iomem_res_desc(start
, end
, flags
, desc
, arg
, func
);
416 EXPORT_SYMBOL_GPL(walk_iomem_res_desc
);
419 * This function calls the @func callback against all memory ranges of type
420 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
421 * Now, this function is only for System RAM, it deals with full ranges and
422 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
425 int walk_system_ram_res(u64 start
, u64 end
, void *arg
,
426 int (*func
)(struct resource
*, void *))
428 unsigned long flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
430 return __walk_iomem_res_desc(start
, end
, flags
, IORES_DESC_NONE
, arg
,
435 * This function calls the @func callback against all memory ranges, which
436 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
438 int walk_mem_res(u64 start
, u64 end
, void *arg
,
439 int (*func
)(struct resource
*, void *))
441 unsigned long flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
443 return __walk_iomem_res_desc(start
, end
, flags
, IORES_DESC_NONE
, arg
,
448 * This function calls the @func callback against all memory ranges of type
449 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
450 * It is to be used only for System RAM.
452 int walk_system_ram_range(unsigned long start_pfn
, unsigned long nr_pages
,
453 void *arg
, int (*func
)(unsigned long, unsigned long, void *))
455 resource_size_t start
, end
;
458 unsigned long pfn
, end_pfn
;
461 start
= (u64
) start_pfn
<< PAGE_SHIFT
;
462 end
= ((u64
)(start_pfn
+ nr_pages
) << PAGE_SHIFT
) - 1;
463 flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
464 while (start
< end
&&
465 !find_next_iomem_res(start
, end
, flags
, IORES_DESC_NONE
, &res
)) {
466 pfn
= PFN_UP(res
.start
);
467 end_pfn
= PFN_DOWN(res
.end
+ 1);
469 ret
= (*func
)(pfn
, end_pfn
- pfn
, arg
);
477 static int __is_ram(unsigned long pfn
, unsigned long nr_pages
, void *arg
)
483 * This generic page_is_ram() returns true if specified address is
484 * registered as System RAM in iomem_resource list.
486 int __weak
page_is_ram(unsigned long pfn
)
488 return walk_system_ram_range(pfn
, 1, NULL
, __is_ram
) == 1;
490 EXPORT_SYMBOL_GPL(page_is_ram
);
492 static int __region_intersects(struct resource
*parent
, resource_size_t start
,
493 size_t size
, unsigned long flags
,
497 int type
= 0; int other
= 0;
501 res
.end
= start
+ size
- 1;
503 for (p
= parent
->child
; p
; p
= p
->sibling
) {
504 bool is_type
= (((p
->flags
& flags
) == flags
) &&
505 ((desc
== IORES_DESC_NONE
) ||
508 if (resource_overlaps(p
, &res
))
509 is_type
? type
++ : other
++;
513 return REGION_DISJOINT
;
516 return REGION_INTERSECTS
;
522 * region_intersects() - determine intersection of region with known resources
523 * @start: region start address
524 * @size: size of region
525 * @flags: flags of resource (in iomem_resource)
526 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
528 * Check if the specified region partially overlaps or fully eclipses a
529 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
530 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
531 * return REGION_MIXED if the region overlaps @flags/@desc and another
532 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
533 * and no other defined resource. Note that REGION_INTERSECTS is also
534 * returned in the case when the specified region overlaps RAM and undefined
537 * region_intersect() is used by memory remapping functions to ensure
538 * the user is not remapping RAM and is a vast speed up over walking
539 * through the resource table page by page.
541 int region_intersects(resource_size_t start
, size_t size
, unsigned long flags
,
546 read_lock(&resource_lock
);
547 ret
= __region_intersects(&iomem_resource
, start
, size
, flags
, desc
);
548 read_unlock(&resource_lock
);
552 EXPORT_SYMBOL_GPL(region_intersects
);
554 void __weak
arch_remove_reservations(struct resource
*avail
)
558 static resource_size_t
simple_align_resource(void *data
,
559 const struct resource
*avail
,
560 resource_size_t size
,
561 resource_size_t align
)
566 static void resource_clip(struct resource
*res
, resource_size_t min
,
569 if (res
->start
< min
)
576 * Find empty slot in the resource tree with the given range and
577 * alignment constraints
579 static int __find_resource(struct resource
*root
, struct resource
*old
,
580 struct resource
*new,
581 resource_size_t size
,
582 struct resource_constraint
*constraint
)
584 struct resource
*this = root
->child
;
585 struct resource tmp
= *new, avail
, alloc
;
587 tmp
.start
= root
->start
;
589 * Skip past an allocated resource that starts at 0, since the assignment
590 * of this->start - 1 to tmp->end below would cause an underflow.
592 if (this && this->start
== root
->start
) {
593 tmp
.start
= (this == old
) ? old
->start
: this->end
+ 1;
594 this = this->sibling
;
598 tmp
.end
= (this == old
) ? this->end
: this->start
- 1;
602 if (tmp
.end
< tmp
.start
)
605 resource_clip(&tmp
, constraint
->min
, constraint
->max
);
606 arch_remove_reservations(&tmp
);
608 /* Check for overflow after ALIGN() */
609 avail
.start
= ALIGN(tmp
.start
, constraint
->align
);
611 avail
.flags
= new->flags
& ~IORESOURCE_UNSET
;
612 if (avail
.start
>= tmp
.start
) {
613 alloc
.flags
= avail
.flags
;
614 alloc
.start
= constraint
->alignf(constraint
->alignf_data
, &avail
,
615 size
, constraint
->align
);
616 alloc
.end
= alloc
.start
+ size
- 1;
617 if (alloc
.start
<= alloc
.end
&&
618 resource_contains(&avail
, &alloc
)) {
619 new->start
= alloc
.start
;
620 new->end
= alloc
.end
;
625 next
: if (!this || this->end
== root
->end
)
629 tmp
.start
= this->end
+ 1;
630 this = this->sibling
;
636 * Find empty slot in the resource tree given range and alignment.
638 static int find_resource(struct resource
*root
, struct resource
*new,
639 resource_size_t size
,
640 struct resource_constraint
*constraint
)
642 return __find_resource(root
, NULL
, new, size
, constraint
);
646 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
647 * The resource will be relocated if the new size cannot be reallocated in the
650 * @root: root resource descriptor
651 * @old: resource descriptor desired by caller
652 * @newsize: new size of the resource descriptor
653 * @constraint: the size and alignment constraints to be met.
655 static int reallocate_resource(struct resource
*root
, struct resource
*old
,
656 resource_size_t newsize
,
657 struct resource_constraint
*constraint
)
660 struct resource
new = *old
;
661 struct resource
*conflict
;
663 write_lock(&resource_lock
);
665 if ((err
= __find_resource(root
, old
, &new, newsize
, constraint
)))
668 if (resource_contains(&new, old
)) {
669 old
->start
= new.start
;
679 if (resource_contains(old
, &new)) {
680 old
->start
= new.start
;
683 __release_resource(old
, true);
685 conflict
= __request_resource(root
, old
);
689 write_unlock(&resource_lock
);
695 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
696 * The resource will be reallocated with a new size if it was already allocated
697 * @root: root resource descriptor
698 * @new: resource descriptor desired by caller
699 * @size: requested resource region size
700 * @min: minimum boundary to allocate
701 * @max: maximum boundary to allocate
702 * @align: alignment requested, in bytes
703 * @alignf: alignment function, optional, called if not NULL
704 * @alignf_data: arbitrary data to pass to the @alignf function
706 int allocate_resource(struct resource
*root
, struct resource
*new,
707 resource_size_t size
, resource_size_t min
,
708 resource_size_t max
, resource_size_t align
,
709 resource_size_t (*alignf
)(void *,
710 const struct resource
*,
716 struct resource_constraint constraint
;
719 alignf
= simple_align_resource
;
721 constraint
.min
= min
;
722 constraint
.max
= max
;
723 constraint
.align
= align
;
724 constraint
.alignf
= alignf
;
725 constraint
.alignf_data
= alignf_data
;
728 /* resource is already allocated, try reallocating with
729 the new constraints */
730 return reallocate_resource(root
, new, size
, &constraint
);
733 write_lock(&resource_lock
);
734 err
= find_resource(root
, new, size
, &constraint
);
735 if (err
>= 0 && __request_resource(root
, new))
737 write_unlock(&resource_lock
);
741 EXPORT_SYMBOL(allocate_resource
);
744 * lookup_resource - find an existing resource by a resource start address
745 * @root: root resource descriptor
746 * @start: resource start address
748 * Returns a pointer to the resource if found, NULL otherwise
750 struct resource
*lookup_resource(struct resource
*root
, resource_size_t start
)
752 struct resource
*res
;
754 read_lock(&resource_lock
);
755 for (res
= root
->child
; res
; res
= res
->sibling
) {
756 if (res
->start
== start
)
759 read_unlock(&resource_lock
);
765 * Insert a resource into the resource tree. If successful, return NULL,
766 * otherwise return the conflicting resource (compare to __request_resource())
768 static struct resource
* __insert_resource(struct resource
*parent
, struct resource
*new)
770 struct resource
*first
, *next
;
772 for (;; parent
= first
) {
773 first
= __request_resource(parent
, new);
779 if (WARN_ON(first
== new)) /* duplicated insertion */
782 if ((first
->start
> new->start
) || (first
->end
< new->end
))
784 if ((first
->start
== new->start
) && (first
->end
== new->end
))
788 for (next
= first
; ; next
= next
->sibling
) {
789 /* Partial overlap? Bad, and unfixable */
790 if (next
->start
< new->start
|| next
->end
> new->end
)
794 if (next
->sibling
->start
> new->end
)
798 new->parent
= parent
;
799 new->sibling
= next
->sibling
;
802 next
->sibling
= NULL
;
803 for (next
= first
; next
; next
= next
->sibling
)
806 if (parent
->child
== first
) {
809 next
= parent
->child
;
810 while (next
->sibling
!= first
)
811 next
= next
->sibling
;
818 * insert_resource_conflict - Inserts resource in the resource tree
819 * @parent: parent of the new resource
820 * @new: new resource to insert
822 * Returns 0 on success, conflict resource if the resource can't be inserted.
824 * This function is equivalent to request_resource_conflict when no conflict
825 * happens. If a conflict happens, and the conflicting resources
826 * entirely fit within the range of the new resource, then the new
827 * resource is inserted and the conflicting resources become children of
830 * This function is intended for producers of resources, such as FW modules
833 struct resource
*insert_resource_conflict(struct resource
*parent
, struct resource
*new)
835 struct resource
*conflict
;
837 write_lock(&resource_lock
);
838 conflict
= __insert_resource(parent
, new);
839 write_unlock(&resource_lock
);
844 * insert_resource - Inserts a resource in the resource tree
845 * @parent: parent of the new resource
846 * @new: new resource to insert
848 * Returns 0 on success, -EBUSY if the resource can't be inserted.
850 * This function is intended for producers of resources, such as FW modules
853 int insert_resource(struct resource
*parent
, struct resource
*new)
855 struct resource
*conflict
;
857 conflict
= insert_resource_conflict(parent
, new);
858 return conflict
? -EBUSY
: 0;
860 EXPORT_SYMBOL_GPL(insert_resource
);
863 * insert_resource_expand_to_fit - Insert a resource into the resource tree
864 * @root: root resource descriptor
865 * @new: new resource to insert
867 * Insert a resource into the resource tree, possibly expanding it in order
868 * to make it encompass any conflicting resources.
870 void insert_resource_expand_to_fit(struct resource
*root
, struct resource
*new)
875 write_lock(&resource_lock
);
877 struct resource
*conflict
;
879 conflict
= __insert_resource(root
, new);
882 if (conflict
== root
)
885 /* Ok, expand resource to cover the conflict, then try again .. */
886 if (conflict
->start
< new->start
)
887 new->start
= conflict
->start
;
888 if (conflict
->end
> new->end
)
889 new->end
= conflict
->end
;
891 printk("Expanded resource %s due to conflict with %s\n", new->name
, conflict
->name
);
893 write_unlock(&resource_lock
);
896 * Not for general consumption, only early boot memory map parsing, PCI
897 * resource discovery, and late discovery of CXL resources are expected
898 * to use this interface. The former are built-in and only the latter,
901 EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit
, CXL
);
904 * remove_resource - Remove a resource in the resource tree
905 * @old: resource to remove
907 * Returns 0 on success, -EINVAL if the resource is not valid.
909 * This function removes a resource previously inserted by insert_resource()
910 * or insert_resource_conflict(), and moves the children (if any) up to
911 * where they were before. insert_resource() and insert_resource_conflict()
912 * insert a new resource, and move any conflicting resources down to the
913 * children of the new resource.
915 * insert_resource(), insert_resource_conflict() and remove_resource() are
916 * intended for producers of resources, such as FW modules and bus drivers.
918 int remove_resource(struct resource
*old
)
922 write_lock(&resource_lock
);
923 retval
= __release_resource(old
, false);
924 write_unlock(&resource_lock
);
927 EXPORT_SYMBOL_GPL(remove_resource
);
929 static int __adjust_resource(struct resource
*res
, resource_size_t start
,
930 resource_size_t size
)
932 struct resource
*tmp
, *parent
= res
->parent
;
933 resource_size_t end
= start
+ size
- 1;
939 if ((start
< parent
->start
) || (end
> parent
->end
))
942 if (res
->sibling
&& (res
->sibling
->start
<= end
))
947 while (tmp
->sibling
!= res
)
949 if (start
<= tmp
->end
)
954 for (tmp
= res
->child
; tmp
; tmp
= tmp
->sibling
)
955 if ((tmp
->start
< start
) || (tmp
->end
> end
))
967 * adjust_resource - modify a resource's start and size
968 * @res: resource to modify
969 * @start: new start value
972 * Given an existing resource, change its start and size to match the
973 * arguments. Returns 0 on success, -EBUSY if it can't fit.
974 * Existing children of the resource are assumed to be immutable.
976 int adjust_resource(struct resource
*res
, resource_size_t start
,
977 resource_size_t size
)
981 write_lock(&resource_lock
);
982 result
= __adjust_resource(res
, start
, size
);
983 write_unlock(&resource_lock
);
986 EXPORT_SYMBOL(adjust_resource
);
989 __reserve_region_with_split(struct resource
*root
, resource_size_t start
,
990 resource_size_t end
, const char *name
)
992 struct resource
*parent
= root
;
993 struct resource
*conflict
;
994 struct resource
*res
= alloc_resource(GFP_ATOMIC
);
995 struct resource
*next_res
= NULL
;
996 int type
= resource_type(root
);
1004 res
->flags
= type
| IORESOURCE_BUSY
;
1005 res
->desc
= IORES_DESC_NONE
;
1009 conflict
= __request_resource(parent
, res
);
1018 /* conflict covered whole area */
1019 if (conflict
->start
<= res
->start
&&
1020 conflict
->end
>= res
->end
) {
1026 /* failed, split and try again */
1027 if (conflict
->start
> res
->start
) {
1029 res
->end
= conflict
->start
- 1;
1030 if (conflict
->end
< end
) {
1031 next_res
= alloc_resource(GFP_ATOMIC
);
1036 next_res
->name
= name
;
1037 next_res
->start
= conflict
->end
+ 1;
1038 next_res
->end
= end
;
1039 next_res
->flags
= type
| IORESOURCE_BUSY
;
1040 next_res
->desc
= IORES_DESC_NONE
;
1043 res
->start
= conflict
->end
+ 1;
1050 reserve_region_with_split(struct resource
*root
, resource_size_t start
,
1051 resource_size_t end
, const char *name
)
1055 write_lock(&resource_lock
);
1056 if (root
->start
> start
|| root
->end
< end
) {
1057 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1058 (unsigned long long)start
, (unsigned long long)end
,
1060 if (start
> root
->end
|| end
< root
->start
)
1063 if (end
> root
->end
)
1065 if (start
< root
->start
)
1066 start
= root
->start
;
1067 pr_err("fixing request to [0x%llx-0x%llx]\n",
1068 (unsigned long long)start
,
1069 (unsigned long long)end
);
1074 __reserve_region_with_split(root
, start
, end
, name
);
1075 write_unlock(&resource_lock
);
1079 * resource_alignment - calculate resource's alignment
1080 * @res: resource pointer
1082 * Returns alignment on success, 0 (invalid alignment) on failure.
1084 resource_size_t
resource_alignment(struct resource
*res
)
1086 switch (res
->flags
& (IORESOURCE_SIZEALIGN
| IORESOURCE_STARTALIGN
)) {
1087 case IORESOURCE_SIZEALIGN
:
1088 return resource_size(res
);
1089 case IORESOURCE_STARTALIGN
:
1097 * This is compatibility stuff for IO resources.
1099 * Note how this, unlike the above, knows about
1100 * the IO flag meanings (busy etc).
1102 * request_region creates a new busy region.
1104 * release_region releases a matching busy region.
1107 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait
);
1109 static struct inode
*iomem_inode
;
1111 #ifdef CONFIG_IO_STRICT_DEVMEM
1112 static void revoke_iomem(struct resource
*res
)
1114 /* pairs with smp_store_release() in iomem_init_inode() */
1115 struct inode
*inode
= smp_load_acquire(&iomem_inode
);
1118 * Check that the initialization has completed. Losing the race
1119 * is ok because it means drivers are claiming resources before
1120 * the fs_initcall level of init and prevent iomem_get_mapping users
1121 * from establishing mappings.
1127 * The expectation is that the driver has successfully marked
1128 * the resource busy by this point, so devmem_is_allowed()
1129 * should start returning false, however for performance this
1130 * does not iterate the entire resource range.
1132 if (devmem_is_allowed(PHYS_PFN(res
->start
)) &&
1133 devmem_is_allowed(PHYS_PFN(res
->end
))) {
1135 * *cringe* iomem=relaxed says "go ahead, what's the
1136 * worst that can happen?"
1141 unmap_mapping_range(inode
->i_mapping
, res
->start
, resource_size(res
), 1);
1144 static void revoke_iomem(struct resource
*res
) {}
1147 struct address_space
*iomem_get_mapping(void)
1150 * This function is only called from file open paths, hence guaranteed
1151 * that fs_initcalls have completed and no need to check for NULL. But
1152 * since revoke_iomem can be called before the initcall we still need
1153 * the barrier to appease checkers.
1155 return smp_load_acquire(&iomem_inode
)->i_mapping
;
1158 static int __request_region_locked(struct resource
*res
, struct resource
*parent
,
1159 resource_size_t start
, resource_size_t n
,
1160 const char *name
, int flags
)
1162 DECLARE_WAITQUEUE(wait
, current
);
1166 res
->end
= start
+ n
- 1;
1169 struct resource
*conflict
;
1171 res
->flags
= resource_type(parent
) | resource_ext_type(parent
);
1172 res
->flags
|= IORESOURCE_BUSY
| flags
;
1173 res
->desc
= parent
->desc
;
1175 conflict
= __request_resource(parent
, res
);
1179 * mm/hmm.c reserves physical addresses which then
1180 * become unavailable to other users. Conflicts are
1181 * not expected. Warn to aid debugging if encountered.
1183 if (conflict
->desc
== IORES_DESC_DEVICE_PRIVATE_MEMORY
) {
1184 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1185 conflict
->name
, conflict
, res
);
1187 if (conflict
!= parent
) {
1188 if (!(conflict
->flags
& IORESOURCE_BUSY
)) {
1193 if (conflict
->flags
& flags
& IORESOURCE_MUXED
) {
1194 add_wait_queue(&muxed_resource_wait
, &wait
);
1195 write_unlock(&resource_lock
);
1196 set_current_state(TASK_UNINTERRUPTIBLE
);
1198 remove_wait_queue(&muxed_resource_wait
, &wait
);
1199 write_lock(&resource_lock
);
1202 /* Uhhuh, that didn't work out.. */
1210 * __request_region - create a new busy resource region
1211 * @parent: parent resource descriptor
1212 * @start: resource start address
1213 * @n: resource region size
1214 * @name: reserving caller's ID string
1215 * @flags: IO resource flags
1217 struct resource
*__request_region(struct resource
*parent
,
1218 resource_size_t start
, resource_size_t n
,
1219 const char *name
, int flags
)
1221 struct resource
*res
= alloc_resource(GFP_KERNEL
);
1227 write_lock(&resource_lock
);
1228 ret
= __request_region_locked(res
, parent
, start
, n
, name
, flags
);
1229 write_unlock(&resource_lock
);
1236 if (parent
== &iomem_resource
)
1241 EXPORT_SYMBOL(__request_region
);
1244 * __release_region - release a previously reserved resource region
1245 * @parent: parent resource descriptor
1246 * @start: resource start address
1247 * @n: resource region size
1249 * The described resource region must match a currently busy region.
1251 void __release_region(struct resource
*parent
, resource_size_t start
,
1254 struct resource
**p
;
1255 resource_size_t end
;
1258 end
= start
+ n
- 1;
1260 write_lock(&resource_lock
);
1263 struct resource
*res
= *p
;
1267 if (res
->start
<= start
&& res
->end
>= end
) {
1268 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1272 if (res
->start
!= start
|| res
->end
!= end
)
1275 write_unlock(&resource_lock
);
1276 if (res
->flags
& IORESOURCE_MUXED
)
1277 wake_up(&muxed_resource_wait
);
1284 write_unlock(&resource_lock
);
1286 printk(KERN_WARNING
"Trying to free nonexistent resource "
1287 "<%016llx-%016llx>\n", (unsigned long long)start
,
1288 (unsigned long long)end
);
1290 EXPORT_SYMBOL(__release_region
);
1292 #ifdef CONFIG_MEMORY_HOTREMOVE
1294 * release_mem_region_adjustable - release a previously reserved memory region
1295 * @start: resource start address
1296 * @size: resource region size
1298 * This interface is intended for memory hot-delete. The requested region
1299 * is released from a currently busy memory resource. The requested region
1300 * must either match exactly or fit into a single busy resource entry. In
1301 * the latter case, the remaining resource is adjusted accordingly.
1302 * Existing children of the busy memory resource must be immutable in the
1306 * - Additional release conditions, such as overlapping region, can be
1307 * supported after they are confirmed as valid cases.
1308 * - When a busy memory resource gets split into two entries, the code
1309 * assumes that all children remain in the lower address entry for
1310 * simplicity. Enhance this logic when necessary.
1312 void release_mem_region_adjustable(resource_size_t start
, resource_size_t size
)
1314 struct resource
*parent
= &iomem_resource
;
1315 struct resource
*new_res
= NULL
;
1316 bool alloc_nofail
= false;
1317 struct resource
**p
;
1318 struct resource
*res
;
1319 resource_size_t end
;
1321 end
= start
+ size
- 1;
1322 if (WARN_ON_ONCE((start
< parent
->start
) || (end
> parent
->end
)))
1326 * We free up quite a lot of memory on memory hotunplug (esp., memap),
1327 * just before releasing the region. This is highly unlikely to
1328 * fail - let's play save and make it never fail as the caller cannot
1329 * perform any error handling (e.g., trying to re-add memory will fail
1333 new_res
= alloc_resource(GFP_KERNEL
| (alloc_nofail
? __GFP_NOFAIL
: 0));
1336 write_lock(&resource_lock
);
1338 while ((res
= *p
)) {
1339 if (res
->start
>= end
)
1342 /* look for the next resource if it does not fit into */
1343 if (res
->start
> start
|| res
->end
< end
) {
1349 * All memory regions added from memory-hotplug path have the
1350 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1351 * this flag, we know that we are dealing with a resource coming
1352 * from HMM/devm. HMM/devm use another mechanism to add/release
1353 * a resource. This goes via devm_request_mem_region and
1354 * devm_release_mem_region.
1355 * HMM/devm take care to release their resources when they want,
1356 * so if we are dealing with them, let us just back off here.
1358 if (!(res
->flags
& IORESOURCE_SYSRAM
)) {
1362 if (!(res
->flags
& IORESOURCE_MEM
))
1365 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1370 /* found the target resource; let's adjust accordingly */
1371 if (res
->start
== start
&& res
->end
== end
) {
1372 /* free the whole entry */
1375 } else if (res
->start
== start
&& res
->end
!= end
) {
1376 /* adjust the start */
1377 WARN_ON_ONCE(__adjust_resource(res
, end
+ 1,
1379 } else if (res
->start
!= start
&& res
->end
== end
) {
1380 /* adjust the end */
1381 WARN_ON_ONCE(__adjust_resource(res
, res
->start
,
1382 start
- res
->start
));
1384 /* split into two entries - we need a new resource */
1386 new_res
= alloc_resource(GFP_ATOMIC
);
1388 alloc_nofail
= true;
1389 write_unlock(&resource_lock
);
1393 new_res
->name
= res
->name
;
1394 new_res
->start
= end
+ 1;
1395 new_res
->end
= res
->end
;
1396 new_res
->flags
= res
->flags
;
1397 new_res
->desc
= res
->desc
;
1398 new_res
->parent
= res
->parent
;
1399 new_res
->sibling
= res
->sibling
;
1400 new_res
->child
= NULL
;
1402 if (WARN_ON_ONCE(__adjust_resource(res
, res
->start
,
1403 start
- res
->start
)))
1405 res
->sibling
= new_res
;
1412 write_unlock(&resource_lock
);
1413 free_resource(new_res
);
1415 #endif /* CONFIG_MEMORY_HOTREMOVE */
1417 #ifdef CONFIG_MEMORY_HOTPLUG
1418 static bool system_ram_resources_mergeable(struct resource
*r1
,
1419 struct resource
*r2
)
1421 /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1422 return r1
->flags
== r2
->flags
&& r1
->end
+ 1 == r2
->start
&&
1423 r1
->name
== r2
->name
&& r1
->desc
== r2
->desc
&&
1424 !r1
->child
&& !r2
->child
;
1428 * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1429 * merge it with adjacent, mergeable resources
1430 * @res: resource descriptor
1432 * This interface is intended for memory hotplug, whereby lots of contiguous
1433 * system ram resources are added (e.g., via add_memory*()) by a driver, and
1434 * the actual resource boundaries are not of interest (e.g., it might be
1435 * relevant for DIMMs). Only resources that are marked mergeable, that have the
1436 * same parent, and that don't have any children are considered. All mergeable
1437 * resources must be immutable during the request.
1440 * - The caller has to make sure that no pointers to resources that are
1441 * marked mergeable are used anymore after this call - the resource might
1442 * be freed and the pointer might be stale!
1443 * - release_mem_region_adjustable() will split on demand on memory hotunplug
1445 void merge_system_ram_resource(struct resource
*res
)
1447 const unsigned long flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
1448 struct resource
*cur
;
1450 if (WARN_ON_ONCE((res
->flags
& flags
) != flags
))
1453 write_lock(&resource_lock
);
1454 res
->flags
|= IORESOURCE_SYSRAM_MERGEABLE
;
1456 /* Try to merge with next item in the list. */
1458 if (cur
&& system_ram_resources_mergeable(res
, cur
)) {
1459 res
->end
= cur
->end
;
1460 res
->sibling
= cur
->sibling
;
1464 /* Try to merge with previous item in the list. */
1465 cur
= res
->parent
->child
;
1466 while (cur
&& cur
->sibling
!= res
)
1468 if (cur
&& system_ram_resources_mergeable(cur
, res
)) {
1469 cur
->end
= res
->end
;
1470 cur
->sibling
= res
->sibling
;
1473 write_unlock(&resource_lock
);
1475 #endif /* CONFIG_MEMORY_HOTPLUG */
1478 * Managed region resource
1480 static void devm_resource_release(struct device
*dev
, void *ptr
)
1482 struct resource
**r
= ptr
;
1484 release_resource(*r
);
1488 * devm_request_resource() - request and reserve an I/O or memory resource
1489 * @dev: device for which to request the resource
1490 * @root: root of the resource tree from which to request the resource
1491 * @new: descriptor of the resource to request
1493 * This is a device-managed version of request_resource(). There is usually
1494 * no need to release resources requested by this function explicitly since
1495 * that will be taken care of when the device is unbound from its driver.
1496 * If for some reason the resource needs to be released explicitly, because
1497 * of ordering issues for example, drivers must call devm_release_resource()
1498 * rather than the regular release_resource().
1500 * When a conflict is detected between any existing resources and the newly
1501 * requested resource, an error message will be printed.
1503 * Returns 0 on success or a negative error code on failure.
1505 int devm_request_resource(struct device
*dev
, struct resource
*root
,
1506 struct resource
*new)
1508 struct resource
*conflict
, **ptr
;
1510 ptr
= devres_alloc(devm_resource_release
, sizeof(*ptr
), GFP_KERNEL
);
1516 conflict
= request_resource_conflict(root
, new);
1518 dev_err(dev
, "resource collision: %pR conflicts with %s %pR\n",
1519 new, conflict
->name
, conflict
);
1524 devres_add(dev
, ptr
);
1527 EXPORT_SYMBOL(devm_request_resource
);
1529 static int devm_resource_match(struct device
*dev
, void *res
, void *data
)
1531 struct resource
**ptr
= res
;
1533 return *ptr
== data
;
1537 * devm_release_resource() - release a previously requested resource
1538 * @dev: device for which to release the resource
1539 * @new: descriptor of the resource to release
1541 * Releases a resource previously requested using devm_request_resource().
1543 void devm_release_resource(struct device
*dev
, struct resource
*new)
1545 WARN_ON(devres_release(dev
, devm_resource_release
, devm_resource_match
,
1548 EXPORT_SYMBOL(devm_release_resource
);
1550 struct region_devres
{
1551 struct resource
*parent
;
1552 resource_size_t start
;
1556 static void devm_region_release(struct device
*dev
, void *res
)
1558 struct region_devres
*this = res
;
1560 __release_region(this->parent
, this->start
, this->n
);
1563 static int devm_region_match(struct device
*dev
, void *res
, void *match_data
)
1565 struct region_devres
*this = res
, *match
= match_data
;
1567 return this->parent
== match
->parent
&&
1568 this->start
== match
->start
&& this->n
== match
->n
;
1572 __devm_request_region(struct device
*dev
, struct resource
*parent
,
1573 resource_size_t start
, resource_size_t n
, const char *name
)
1575 struct region_devres
*dr
= NULL
;
1576 struct resource
*res
;
1578 dr
= devres_alloc(devm_region_release
, sizeof(struct region_devres
),
1583 dr
->parent
= parent
;
1587 res
= __request_region(parent
, start
, n
, name
, 0);
1589 devres_add(dev
, dr
);
1595 EXPORT_SYMBOL(__devm_request_region
);
1597 void __devm_release_region(struct device
*dev
, struct resource
*parent
,
1598 resource_size_t start
, resource_size_t n
)
1600 struct region_devres match_data
= { parent
, start
, n
};
1602 __release_region(parent
, start
, n
);
1603 WARN_ON(devres_destroy(dev
, devm_region_release
, devm_region_match
,
1606 EXPORT_SYMBOL(__devm_release_region
);
1609 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1611 #define MAXRESERVE 4
1612 static int __init
reserve_setup(char *str
)
1614 static int reserved
;
1615 static struct resource reserve
[MAXRESERVE
];
1618 unsigned int io_start
, io_num
;
1620 struct resource
*parent
;
1622 if (get_option(&str
, &io_start
) != 2)
1624 if (get_option(&str
, &io_num
) == 0)
1626 if (x
< MAXRESERVE
) {
1627 struct resource
*res
= reserve
+ x
;
1630 * If the region starts below 0x10000, we assume it's
1631 * I/O port space; otherwise assume it's memory.
1633 if (io_start
< 0x10000) {
1634 res
->flags
= IORESOURCE_IO
;
1635 parent
= &ioport_resource
;
1637 res
->flags
= IORESOURCE_MEM
;
1638 parent
= &iomem_resource
;
1640 res
->name
= "reserved";
1641 res
->start
= io_start
;
1642 res
->end
= io_start
+ io_num
- 1;
1643 res
->flags
|= IORESOURCE_BUSY
;
1644 res
->desc
= IORES_DESC_NONE
;
1646 if (request_resource(parent
, res
) == 0)
1652 __setup("reserve=", reserve_setup
);
1655 * Check if the requested addr and size spans more than any slot in the
1656 * iomem resource tree.
1658 int iomem_map_sanity_check(resource_size_t addr
, unsigned long size
)
1660 struct resource
*p
= &iomem_resource
;
1664 read_lock(&resource_lock
);
1665 for (p
= p
->child
; p
; p
= r_next(NULL
, p
, &l
)) {
1667 * We can probably skip the resources without
1668 * IORESOURCE_IO attribute?
1670 if (p
->start
>= addr
+ size
)
1674 if (PFN_DOWN(p
->start
) <= PFN_DOWN(addr
) &&
1675 PFN_DOWN(p
->end
) >= PFN_DOWN(addr
+ size
- 1))
1678 * if a resource is "BUSY", it's not a hardware resource
1679 * but a driver mapping of such a resource; we don't want
1680 * to warn for those; some drivers legitimately map only
1681 * partial hardware resources. (example: vesafb)
1683 if (p
->flags
& IORESOURCE_BUSY
)
1686 printk(KERN_WARNING
"resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1687 (unsigned long long)addr
,
1688 (unsigned long long)(addr
+ size
- 1),
1693 read_unlock(&resource_lock
);
1698 #ifdef CONFIG_STRICT_DEVMEM
1699 static int strict_iomem_checks
= 1;
1701 static int strict_iomem_checks
;
1705 * Check if an address is exclusive to the kernel and must not be mapped to
1706 * user space, for example, via /dev/mem.
1708 * Returns true if exclusive to the kernel, otherwise returns false.
1710 bool iomem_is_exclusive(u64 addr
)
1712 const unsigned int exclusive_system_ram
= IORESOURCE_SYSTEM_RAM
|
1713 IORESOURCE_EXCLUSIVE
;
1714 bool skip_children
= false, err
= false;
1715 int size
= PAGE_SIZE
;
1718 addr
= addr
& PAGE_MASK
;
1720 read_lock(&resource_lock
);
1721 for_each_resource(&iomem_resource
, p
, skip_children
) {
1722 if (p
->start
>= addr
+ size
)
1724 if (p
->end
< addr
) {
1725 skip_children
= true;
1728 skip_children
= false;
1731 * IORESOURCE_SYSTEM_RAM resources are exclusive if
1732 * IORESOURCE_EXCLUSIVE is set, even if they
1733 * are not busy and even if "iomem=relaxed" is set. The
1734 * responsible driver dynamically adds/removes system RAM within
1735 * such an area and uncontrolled access is dangerous.
1737 if ((p
->flags
& exclusive_system_ram
) == exclusive_system_ram
) {
1743 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1744 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1747 if (!strict_iomem_checks
|| !(p
->flags
& IORESOURCE_BUSY
))
1749 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM
)
1750 || p
->flags
& IORESOURCE_EXCLUSIVE
) {
1755 read_unlock(&resource_lock
);
1760 struct resource_entry
*resource_list_create_entry(struct resource
*res
,
1763 struct resource_entry
*entry
;
1765 entry
= kzalloc(sizeof(*entry
) + extra_size
, GFP_KERNEL
);
1767 INIT_LIST_HEAD(&entry
->node
);
1768 entry
->res
= res
? res
: &entry
->__res
;
1773 EXPORT_SYMBOL(resource_list_create_entry
);
1775 void resource_list_free(struct list_head
*head
)
1777 struct resource_entry
*entry
, *tmp
;
1779 list_for_each_entry_safe(entry
, tmp
, head
, node
)
1780 resource_list_destroy_entry(entry
);
1782 EXPORT_SYMBOL(resource_list_free
);
1784 #ifdef CONFIG_GET_FREE_REGION
1785 #define GFR_DESCENDING (1UL << 0)
1786 #define GFR_REQUEST_REGION (1UL << 1)
1787 #define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT)
1789 static resource_size_t
gfr_start(struct resource
*base
, resource_size_t size
,
1790 resource_size_t align
, unsigned long flags
)
1792 if (flags
& GFR_DESCENDING
) {
1793 resource_size_t end
;
1795 end
= min_t(resource_size_t
, base
->end
,
1796 (1ULL << MAX_PHYSMEM_BITS
) - 1);
1797 return end
- size
+ 1;
1800 return ALIGN(base
->start
, align
);
1803 static bool gfr_continue(struct resource
*base
, resource_size_t addr
,
1804 resource_size_t size
, unsigned long flags
)
1806 if (flags
& GFR_DESCENDING
)
1807 return addr
> size
&& addr
>= base
->start
;
1809 * In the ascend case be careful that the last increment by
1810 * @size did not wrap 0.
1812 return addr
> addr
- size
&&
1813 addr
<= min_t(resource_size_t
, base
->end
,
1814 (1ULL << MAX_PHYSMEM_BITS
) - 1);
1817 static resource_size_t
gfr_next(resource_size_t addr
, resource_size_t size
,
1818 unsigned long flags
)
1820 if (flags
& GFR_DESCENDING
)
1825 static void remove_free_mem_region(void *_res
)
1827 struct resource
*res
= _res
;
1830 remove_resource(res
);
1834 static struct resource
*
1835 get_free_mem_region(struct device
*dev
, struct resource
*base
,
1836 resource_size_t size
, const unsigned long align
,
1837 const char *name
, const unsigned long desc
,
1838 const unsigned long flags
)
1840 resource_size_t addr
;
1841 struct resource
*res
;
1842 struct region_devres
*dr
= NULL
;
1844 size
= ALIGN(size
, align
);
1846 res
= alloc_resource(GFP_KERNEL
);
1848 return ERR_PTR(-ENOMEM
);
1850 if (dev
&& (flags
& GFR_REQUEST_REGION
)) {
1851 dr
= devres_alloc(devm_region_release
,
1852 sizeof(struct region_devres
), GFP_KERNEL
);
1855 return ERR_PTR(-ENOMEM
);
1858 if (devm_add_action_or_reset(dev
, remove_free_mem_region
, res
))
1859 return ERR_PTR(-ENOMEM
);
1862 write_lock(&resource_lock
);
1863 for (addr
= gfr_start(base
, size
, align
, flags
);
1864 gfr_continue(base
, addr
, size
, flags
);
1865 addr
= gfr_next(addr
, size
, flags
)) {
1866 if (__region_intersects(base
, addr
, size
, 0, IORES_DESC_NONE
) !=
1870 if (flags
& GFR_REQUEST_REGION
) {
1871 if (__request_region_locked(res
, &iomem_resource
, addr
,
1876 dr
->parent
= &iomem_resource
;
1879 devres_add(dev
, dr
);
1883 write_unlock(&resource_lock
);
1887 * A driver is claiming this region so revoke any
1893 res
->end
= addr
+ size
- 1;
1896 res
->flags
= IORESOURCE_MEM
;
1899 * Only succeed if the resource hosts an exclusive
1900 * range after the insert
1902 if (__insert_resource(base
, res
) || res
->child
)
1905 write_unlock(&resource_lock
);
1910 write_unlock(&resource_lock
);
1912 if (flags
& GFR_REQUEST_REGION
) {
1916 devm_release_action(dev
, remove_free_mem_region
, res
);
1918 return ERR_PTR(-ERANGE
);
1922 * devm_request_free_mem_region - find free region for device private memory
1924 * @dev: device struct to bind the resource to
1925 * @size: size in bytes of the device memory to add
1926 * @base: resource tree to look in
1928 * This function tries to find an empty range of physical address big enough to
1929 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1930 * memory, which in turn allocates struct pages.
1932 struct resource
*devm_request_free_mem_region(struct device
*dev
,
1933 struct resource
*base
, unsigned long size
)
1935 unsigned long flags
= GFR_DESCENDING
| GFR_REQUEST_REGION
;
1937 return get_free_mem_region(dev
, base
, size
, GFR_DEFAULT_ALIGN
,
1939 IORES_DESC_DEVICE_PRIVATE_MEMORY
, flags
);
1941 EXPORT_SYMBOL_GPL(devm_request_free_mem_region
);
1943 struct resource
*request_free_mem_region(struct resource
*base
,
1944 unsigned long size
, const char *name
)
1946 unsigned long flags
= GFR_DESCENDING
| GFR_REQUEST_REGION
;
1948 return get_free_mem_region(NULL
, base
, size
, GFR_DEFAULT_ALIGN
, name
,
1949 IORES_DESC_DEVICE_PRIVATE_MEMORY
, flags
);
1951 EXPORT_SYMBOL_GPL(request_free_mem_region
);
1954 * alloc_free_mem_region - find a free region relative to @base
1955 * @base: resource that will parent the new resource
1956 * @size: size in bytes of memory to allocate from @base
1957 * @align: alignment requirements for the allocation
1958 * @name: resource name
1960 * Buses like CXL, that can dynamically instantiate new memory regions,
1961 * need a method to allocate physical address space for those regions.
1962 * Allocate and insert a new resource to cover a free, unclaimed by a
1963 * descendant of @base, range in the span of @base.
1965 struct resource
*alloc_free_mem_region(struct resource
*base
,
1966 unsigned long size
, unsigned long align
,
1969 /* Default of ascending direction and insert resource */
1970 unsigned long flags
= 0;
1972 return get_free_mem_region(NULL
, base
, size
, align
, name
,
1973 IORES_DESC_NONE
, flags
);
1975 EXPORT_SYMBOL_NS_GPL(alloc_free_mem_region
, CXL
);
1976 #endif /* CONFIG_GET_FREE_REGION */
1978 static int __init
strict_iomem(char *str
)
1980 if (strstr(str
, "relaxed"))
1981 strict_iomem_checks
= 0;
1982 if (strstr(str
, "strict"))
1983 strict_iomem_checks
= 1;
1987 static int iomem_fs_init_fs_context(struct fs_context
*fc
)
1989 return init_pseudo(fc
, DEVMEM_MAGIC
) ? 0 : -ENOMEM
;
1992 static struct file_system_type iomem_fs_type
= {
1994 .owner
= THIS_MODULE
,
1995 .init_fs_context
= iomem_fs_init_fs_context
,
1996 .kill_sb
= kill_anon_super
,
1999 static int __init
iomem_init_inode(void)
2001 static struct vfsmount
*iomem_vfs_mount
;
2002 static int iomem_fs_cnt
;
2003 struct inode
*inode
;
2006 rc
= simple_pin_fs(&iomem_fs_type
, &iomem_vfs_mount
, &iomem_fs_cnt
);
2008 pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc
);
2012 inode
= alloc_anon_inode(iomem_vfs_mount
->mnt_sb
);
2013 if (IS_ERR(inode
)) {
2014 rc
= PTR_ERR(inode
);
2015 pr_err("Cannot allocate inode for iomem: %d\n", rc
);
2016 simple_release_fs(&iomem_vfs_mount
, &iomem_fs_cnt
);
2021 * Publish iomem revocation inode initialized.
2022 * Pairs with smp_load_acquire() in revoke_iomem().
2024 smp_store_release(&iomem_inode
, inode
);
2029 fs_initcall(iomem_init_inode
);
2031 __setup("iomem=", strict_iomem
);