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>
30 #include <linux/string.h>
31 #include <linux/vmalloc.h>
35 struct resource ioport_resource
= {
38 .end
= IO_SPACE_LIMIT
,
39 .flags
= IORESOURCE_IO
,
41 EXPORT_SYMBOL(ioport_resource
);
43 struct resource iomem_resource
= {
47 .flags
= IORESOURCE_MEM
,
49 EXPORT_SYMBOL(iomem_resource
);
51 /* constraints to be met while allocating resources */
52 struct resource_constraint
{
53 resource_size_t min
, max
, align
;
54 resource_size_t (*alignf
)(void *, const struct resource
*,
55 resource_size_t
, resource_size_t
);
59 static DEFINE_RWLOCK(resource_lock
);
61 static struct resource
*next_resource(struct resource
*p
, bool skip_children
)
63 if (!skip_children
&& p
->child
)
65 while (!p
->sibling
&& p
->parent
)
70 #define for_each_resource(_root, _p, _skip_children) \
71 for ((_p) = (_root)->child; (_p); (_p) = next_resource(_p, _skip_children))
75 enum { MAX_IORES_LEVEL
= 5 };
77 static void *r_start(struct seq_file
*m
, loff_t
*pos
)
78 __acquires(resource_lock
)
80 struct resource
*root
= pde_data(file_inode(m
->file
));
84 read_lock(&resource_lock
);
85 for_each_resource(root
, p
, false) {
93 static void *r_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
95 struct resource
*p
= v
;
99 return (void *)next_resource(p
, false);
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_each_resource(&iomem_resource
, p
, false) {
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, being a variant of walk_system_ram_res(), calls the @func
436 * callback against all memory ranges of type System RAM which are marked as
437 * IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY in reversed order, i.e., from
440 int walk_system_ram_res_rev(u64 start
, u64 end
, void *arg
,
441 int (*func
)(struct resource
*, void *))
443 struct resource res
, *rams
;
444 int rams_size
= 16, i
;
449 rams
= kvcalloc(rams_size
, sizeof(struct resource
), GFP_KERNEL
);
453 flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
455 while ((start
< end
) &&
456 (!find_next_iomem_res(start
, end
, flags
, IORES_DESC_NONE
, &res
))) {
457 if (i
>= rams_size
) {
459 struct resource
*rams_new
;
461 rams_new
= kvrealloc(rams
, rams_size
* sizeof(struct resource
),
462 (rams_size
+ 16) * sizeof(struct resource
),
471 rams
[i
].start
= res
.start
;
472 rams
[i
++].end
= res
.end
;
478 for (i
--; i
>= 0; i
--) {
479 ret
= (*func
)(&rams
[i
], arg
);
490 * This function calls the @func callback against all memory ranges, which
491 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
493 int walk_mem_res(u64 start
, u64 end
, void *arg
,
494 int (*func
)(struct resource
*, void *))
496 unsigned long flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
498 return __walk_iomem_res_desc(start
, end
, flags
, IORES_DESC_NONE
, arg
,
503 * This function calls the @func callback against all memory ranges of type
504 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
505 * It is to be used only for System RAM.
507 int walk_system_ram_range(unsigned long start_pfn
, unsigned long nr_pages
,
508 void *arg
, int (*func
)(unsigned long, unsigned long, void *))
510 resource_size_t start
, end
;
513 unsigned long pfn
, end_pfn
;
516 start
= (u64
) start_pfn
<< PAGE_SHIFT
;
517 end
= ((u64
)(start_pfn
+ nr_pages
) << PAGE_SHIFT
) - 1;
518 flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
519 while (start
< end
&&
520 !find_next_iomem_res(start
, end
, flags
, IORES_DESC_NONE
, &res
)) {
521 pfn
= PFN_UP(res
.start
);
522 end_pfn
= PFN_DOWN(res
.end
+ 1);
524 ret
= (*func
)(pfn
, end_pfn
- pfn
, arg
);
532 static int __is_ram(unsigned long pfn
, unsigned long nr_pages
, void *arg
)
538 * This generic page_is_ram() returns true if specified address is
539 * registered as System RAM in iomem_resource list.
541 int __weak
page_is_ram(unsigned long pfn
)
543 return walk_system_ram_range(pfn
, 1, NULL
, __is_ram
) == 1;
545 EXPORT_SYMBOL_GPL(page_is_ram
);
547 static int __region_intersects(struct resource
*parent
, resource_size_t start
,
548 size_t size
, unsigned long flags
,
552 int type
= 0; int other
= 0;
556 res
.end
= start
+ size
- 1;
558 for (p
= parent
->child
; p
; p
= p
->sibling
) {
559 bool is_type
= (((p
->flags
& flags
) == flags
) &&
560 ((desc
== IORES_DESC_NONE
) ||
563 if (resource_overlaps(p
, &res
))
564 is_type
? type
++ : other
++;
568 return REGION_DISJOINT
;
571 return REGION_INTERSECTS
;
577 * region_intersects() - determine intersection of region with known resources
578 * @start: region start address
579 * @size: size of region
580 * @flags: flags of resource (in iomem_resource)
581 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
583 * Check if the specified region partially overlaps or fully eclipses a
584 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
585 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
586 * return REGION_MIXED if the region overlaps @flags/@desc and another
587 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
588 * and no other defined resource. Note that REGION_INTERSECTS is also
589 * returned in the case when the specified region overlaps RAM and undefined
592 * region_intersect() is used by memory remapping functions to ensure
593 * the user is not remapping RAM and is a vast speed up over walking
594 * through the resource table page by page.
596 int region_intersects(resource_size_t start
, size_t size
, unsigned long flags
,
601 read_lock(&resource_lock
);
602 ret
= __region_intersects(&iomem_resource
, start
, size
, flags
, desc
);
603 read_unlock(&resource_lock
);
607 EXPORT_SYMBOL_GPL(region_intersects
);
609 void __weak
arch_remove_reservations(struct resource
*avail
)
613 static resource_size_t
simple_align_resource(void *data
,
614 const struct resource
*avail
,
615 resource_size_t size
,
616 resource_size_t align
)
621 static void resource_clip(struct resource
*res
, resource_size_t min
,
624 if (res
->start
< min
)
631 * Find empty slot in the resource tree with the given range and
632 * alignment constraints
634 static int __find_resource(struct resource
*root
, struct resource
*old
,
635 struct resource
*new,
636 resource_size_t size
,
637 struct resource_constraint
*constraint
)
639 struct resource
*this = root
->child
;
640 struct resource tmp
= *new, avail
, alloc
;
642 tmp
.start
= root
->start
;
644 * Skip past an allocated resource that starts at 0, since the assignment
645 * of this->start - 1 to tmp->end below would cause an underflow.
647 if (this && this->start
== root
->start
) {
648 tmp
.start
= (this == old
) ? old
->start
: this->end
+ 1;
649 this = this->sibling
;
653 tmp
.end
= (this == old
) ? this->end
: this->start
- 1;
657 if (tmp
.end
< tmp
.start
)
660 resource_clip(&tmp
, constraint
->min
, constraint
->max
);
661 arch_remove_reservations(&tmp
);
663 /* Check for overflow after ALIGN() */
664 avail
.start
= ALIGN(tmp
.start
, constraint
->align
);
666 avail
.flags
= new->flags
& ~IORESOURCE_UNSET
;
667 if (avail
.start
>= tmp
.start
) {
668 alloc
.flags
= avail
.flags
;
669 alloc
.start
= constraint
->alignf(constraint
->alignf_data
, &avail
,
670 size
, constraint
->align
);
671 alloc
.end
= alloc
.start
+ size
- 1;
672 if (alloc
.start
<= alloc
.end
&&
673 resource_contains(&avail
, &alloc
)) {
674 new->start
= alloc
.start
;
675 new->end
= alloc
.end
;
680 next
: if (!this || this->end
== root
->end
)
684 tmp
.start
= this->end
+ 1;
685 this = this->sibling
;
691 * Find empty slot in the resource tree given range and alignment.
693 static int find_resource(struct resource
*root
, struct resource
*new,
694 resource_size_t size
,
695 struct resource_constraint
*constraint
)
697 return __find_resource(root
, NULL
, new, size
, constraint
);
701 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
702 * The resource will be relocated if the new size cannot be reallocated in the
705 * @root: root resource descriptor
706 * @old: resource descriptor desired by caller
707 * @newsize: new size of the resource descriptor
708 * @constraint: the size and alignment constraints to be met.
710 static int reallocate_resource(struct resource
*root
, struct resource
*old
,
711 resource_size_t newsize
,
712 struct resource_constraint
*constraint
)
715 struct resource
new = *old
;
716 struct resource
*conflict
;
718 write_lock(&resource_lock
);
720 if ((err
= __find_resource(root
, old
, &new, newsize
, constraint
)))
723 if (resource_contains(&new, old
)) {
724 old
->start
= new.start
;
734 if (resource_contains(old
, &new)) {
735 old
->start
= new.start
;
738 __release_resource(old
, true);
740 conflict
= __request_resource(root
, old
);
744 write_unlock(&resource_lock
);
750 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
751 * The resource will be reallocated with a new size if it was already allocated
752 * @root: root resource descriptor
753 * @new: resource descriptor desired by caller
754 * @size: requested resource region size
755 * @min: minimum boundary to allocate
756 * @max: maximum boundary to allocate
757 * @align: alignment requested, in bytes
758 * @alignf: alignment function, optional, called if not NULL
759 * @alignf_data: arbitrary data to pass to the @alignf function
761 int allocate_resource(struct resource
*root
, struct resource
*new,
762 resource_size_t size
, resource_size_t min
,
763 resource_size_t max
, resource_size_t align
,
764 resource_size_t (*alignf
)(void *,
765 const struct resource
*,
771 struct resource_constraint constraint
;
774 alignf
= simple_align_resource
;
776 constraint
.min
= min
;
777 constraint
.max
= max
;
778 constraint
.align
= align
;
779 constraint
.alignf
= alignf
;
780 constraint
.alignf_data
= alignf_data
;
783 /* resource is already allocated, try reallocating with
784 the new constraints */
785 return reallocate_resource(root
, new, size
, &constraint
);
788 write_lock(&resource_lock
);
789 err
= find_resource(root
, new, size
, &constraint
);
790 if (err
>= 0 && __request_resource(root
, new))
792 write_unlock(&resource_lock
);
796 EXPORT_SYMBOL(allocate_resource
);
799 * lookup_resource - find an existing resource by a resource start address
800 * @root: root resource descriptor
801 * @start: resource start address
803 * Returns a pointer to the resource if found, NULL otherwise
805 struct resource
*lookup_resource(struct resource
*root
, resource_size_t start
)
807 struct resource
*res
;
809 read_lock(&resource_lock
);
810 for (res
= root
->child
; res
; res
= res
->sibling
) {
811 if (res
->start
== start
)
814 read_unlock(&resource_lock
);
820 * Insert a resource into the resource tree. If successful, return NULL,
821 * otherwise return the conflicting resource (compare to __request_resource())
823 static struct resource
* __insert_resource(struct resource
*parent
, struct resource
*new)
825 struct resource
*first
, *next
;
827 for (;; parent
= first
) {
828 first
= __request_resource(parent
, new);
834 if (WARN_ON(first
== new)) /* duplicated insertion */
837 if ((first
->start
> new->start
) || (first
->end
< new->end
))
839 if ((first
->start
== new->start
) && (first
->end
== new->end
))
843 for (next
= first
; ; next
= next
->sibling
) {
844 /* Partial overlap? Bad, and unfixable */
845 if (next
->start
< new->start
|| next
->end
> new->end
)
849 if (next
->sibling
->start
> new->end
)
853 new->parent
= parent
;
854 new->sibling
= next
->sibling
;
857 next
->sibling
= NULL
;
858 for (next
= first
; next
; next
= next
->sibling
)
861 if (parent
->child
== first
) {
864 next
= parent
->child
;
865 while (next
->sibling
!= first
)
866 next
= next
->sibling
;
873 * insert_resource_conflict - Inserts resource in the resource tree
874 * @parent: parent of the new resource
875 * @new: new resource to insert
877 * Returns 0 on success, conflict resource if the resource can't be inserted.
879 * This function is equivalent to request_resource_conflict when no conflict
880 * happens. If a conflict happens, and the conflicting resources
881 * entirely fit within the range of the new resource, then the new
882 * resource is inserted and the conflicting resources become children of
885 * This function is intended for producers of resources, such as FW modules
888 struct resource
*insert_resource_conflict(struct resource
*parent
, struct resource
*new)
890 struct resource
*conflict
;
892 write_lock(&resource_lock
);
893 conflict
= __insert_resource(parent
, new);
894 write_unlock(&resource_lock
);
899 * insert_resource - Inserts a resource in the resource tree
900 * @parent: parent of the new resource
901 * @new: new resource to insert
903 * Returns 0 on success, -EBUSY if the resource can't be inserted.
905 * This function is intended for producers of resources, such as FW modules
908 int insert_resource(struct resource
*parent
, struct resource
*new)
910 struct resource
*conflict
;
912 conflict
= insert_resource_conflict(parent
, new);
913 return conflict
? -EBUSY
: 0;
915 EXPORT_SYMBOL_GPL(insert_resource
);
918 * insert_resource_expand_to_fit - Insert a resource into the resource tree
919 * @root: root resource descriptor
920 * @new: new resource to insert
922 * Insert a resource into the resource tree, possibly expanding it in order
923 * to make it encompass any conflicting resources.
925 void insert_resource_expand_to_fit(struct resource
*root
, struct resource
*new)
930 write_lock(&resource_lock
);
932 struct resource
*conflict
;
934 conflict
= __insert_resource(root
, new);
937 if (conflict
== root
)
940 /* Ok, expand resource to cover the conflict, then try again .. */
941 if (conflict
->start
< new->start
)
942 new->start
= conflict
->start
;
943 if (conflict
->end
> new->end
)
944 new->end
= conflict
->end
;
946 pr_info("Expanded resource %s due to conflict with %s\n", new->name
, conflict
->name
);
948 write_unlock(&resource_lock
);
951 * Not for general consumption, only early boot memory map parsing, PCI
952 * resource discovery, and late discovery of CXL resources are expected
953 * to use this interface. The former are built-in and only the latter,
956 EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit
, CXL
);
959 * remove_resource - Remove a resource in the resource tree
960 * @old: resource to remove
962 * Returns 0 on success, -EINVAL if the resource is not valid.
964 * This function removes a resource previously inserted by insert_resource()
965 * or insert_resource_conflict(), and moves the children (if any) up to
966 * where they were before. insert_resource() and insert_resource_conflict()
967 * insert a new resource, and move any conflicting resources down to the
968 * children of the new resource.
970 * insert_resource(), insert_resource_conflict() and remove_resource() are
971 * intended for producers of resources, such as FW modules and bus drivers.
973 int remove_resource(struct resource
*old
)
977 write_lock(&resource_lock
);
978 retval
= __release_resource(old
, false);
979 write_unlock(&resource_lock
);
982 EXPORT_SYMBOL_GPL(remove_resource
);
984 static int __adjust_resource(struct resource
*res
, resource_size_t start
,
985 resource_size_t size
)
987 struct resource
*tmp
, *parent
= res
->parent
;
988 resource_size_t end
= start
+ size
- 1;
994 if ((start
< parent
->start
) || (end
> parent
->end
))
997 if (res
->sibling
&& (res
->sibling
->start
<= end
))
1000 tmp
= parent
->child
;
1002 while (tmp
->sibling
!= res
)
1004 if (start
<= tmp
->end
)
1009 for (tmp
= res
->child
; tmp
; tmp
= tmp
->sibling
)
1010 if ((tmp
->start
< start
) || (tmp
->end
> end
))
1022 * adjust_resource - modify a resource's start and size
1023 * @res: resource to modify
1024 * @start: new start value
1027 * Given an existing resource, change its start and size to match the
1028 * arguments. Returns 0 on success, -EBUSY if it can't fit.
1029 * Existing children of the resource are assumed to be immutable.
1031 int adjust_resource(struct resource
*res
, resource_size_t start
,
1032 resource_size_t size
)
1036 write_lock(&resource_lock
);
1037 result
= __adjust_resource(res
, start
, size
);
1038 write_unlock(&resource_lock
);
1041 EXPORT_SYMBOL(adjust_resource
);
1044 __reserve_region_with_split(struct resource
*root
, resource_size_t start
,
1045 resource_size_t end
, const char *name
)
1047 struct resource
*parent
= root
;
1048 struct resource
*conflict
;
1049 struct resource
*res
= alloc_resource(GFP_ATOMIC
);
1050 struct resource
*next_res
= NULL
;
1051 int type
= resource_type(root
);
1059 res
->flags
= type
| IORESOURCE_BUSY
;
1060 res
->desc
= IORES_DESC_NONE
;
1064 conflict
= __request_resource(parent
, res
);
1073 /* conflict covered whole area */
1074 if (conflict
->start
<= res
->start
&&
1075 conflict
->end
>= res
->end
) {
1081 /* failed, split and try again */
1082 if (conflict
->start
> res
->start
) {
1084 res
->end
= conflict
->start
- 1;
1085 if (conflict
->end
< end
) {
1086 next_res
= alloc_resource(GFP_ATOMIC
);
1091 next_res
->name
= name
;
1092 next_res
->start
= conflict
->end
+ 1;
1093 next_res
->end
= end
;
1094 next_res
->flags
= type
| IORESOURCE_BUSY
;
1095 next_res
->desc
= IORES_DESC_NONE
;
1098 res
->start
= conflict
->end
+ 1;
1105 reserve_region_with_split(struct resource
*root
, resource_size_t start
,
1106 resource_size_t end
, const char *name
)
1110 write_lock(&resource_lock
);
1111 if (root
->start
> start
|| root
->end
< end
) {
1112 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1113 (unsigned long long)start
, (unsigned long long)end
,
1115 if (start
> root
->end
|| end
< root
->start
)
1118 if (end
> root
->end
)
1120 if (start
< root
->start
)
1121 start
= root
->start
;
1122 pr_err("fixing request to [0x%llx-0x%llx]\n",
1123 (unsigned long long)start
,
1124 (unsigned long long)end
);
1129 __reserve_region_with_split(root
, start
, end
, name
);
1130 write_unlock(&resource_lock
);
1134 * resource_alignment - calculate resource's alignment
1135 * @res: resource pointer
1137 * Returns alignment on success, 0 (invalid alignment) on failure.
1139 resource_size_t
resource_alignment(struct resource
*res
)
1141 switch (res
->flags
& (IORESOURCE_SIZEALIGN
| IORESOURCE_STARTALIGN
)) {
1142 case IORESOURCE_SIZEALIGN
:
1143 return resource_size(res
);
1144 case IORESOURCE_STARTALIGN
:
1152 * This is compatibility stuff for IO resources.
1154 * Note how this, unlike the above, knows about
1155 * the IO flag meanings (busy etc).
1157 * request_region creates a new busy region.
1159 * release_region releases a matching busy region.
1162 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait
);
1164 static struct inode
*iomem_inode
;
1166 #ifdef CONFIG_IO_STRICT_DEVMEM
1167 static void revoke_iomem(struct resource
*res
)
1169 /* pairs with smp_store_release() in iomem_init_inode() */
1170 struct inode
*inode
= smp_load_acquire(&iomem_inode
);
1173 * Check that the initialization has completed. Losing the race
1174 * is ok because it means drivers are claiming resources before
1175 * the fs_initcall level of init and prevent iomem_get_mapping users
1176 * from establishing mappings.
1182 * The expectation is that the driver has successfully marked
1183 * the resource busy by this point, so devmem_is_allowed()
1184 * should start returning false, however for performance this
1185 * does not iterate the entire resource range.
1187 if (devmem_is_allowed(PHYS_PFN(res
->start
)) &&
1188 devmem_is_allowed(PHYS_PFN(res
->end
))) {
1190 * *cringe* iomem=relaxed says "go ahead, what's the
1191 * worst that can happen?"
1196 unmap_mapping_range(inode
->i_mapping
, res
->start
, resource_size(res
), 1);
1199 static void revoke_iomem(struct resource
*res
) {}
1202 struct address_space
*iomem_get_mapping(void)
1205 * This function is only called from file open paths, hence guaranteed
1206 * that fs_initcalls have completed and no need to check for NULL. But
1207 * since revoke_iomem can be called before the initcall we still need
1208 * the barrier to appease checkers.
1210 return smp_load_acquire(&iomem_inode
)->i_mapping
;
1213 static int __request_region_locked(struct resource
*res
, struct resource
*parent
,
1214 resource_size_t start
, resource_size_t n
,
1215 const char *name
, int flags
)
1217 DECLARE_WAITQUEUE(wait
, current
);
1221 res
->end
= start
+ n
- 1;
1224 struct resource
*conflict
;
1226 res
->flags
= resource_type(parent
) | resource_ext_type(parent
);
1227 res
->flags
|= IORESOURCE_BUSY
| flags
;
1228 res
->desc
= parent
->desc
;
1230 conflict
= __request_resource(parent
, res
);
1234 * mm/hmm.c reserves physical addresses which then
1235 * become unavailable to other users. Conflicts are
1236 * not expected. Warn to aid debugging if encountered.
1238 if (conflict
->desc
== IORES_DESC_DEVICE_PRIVATE_MEMORY
) {
1239 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1240 conflict
->name
, conflict
, res
);
1242 if (conflict
!= parent
) {
1243 if (!(conflict
->flags
& IORESOURCE_BUSY
)) {
1248 if (conflict
->flags
& flags
& IORESOURCE_MUXED
) {
1249 add_wait_queue(&muxed_resource_wait
, &wait
);
1250 write_unlock(&resource_lock
);
1251 set_current_state(TASK_UNINTERRUPTIBLE
);
1253 remove_wait_queue(&muxed_resource_wait
, &wait
);
1254 write_lock(&resource_lock
);
1257 /* Uhhuh, that didn't work out.. */
1265 * __request_region - create a new busy resource region
1266 * @parent: parent resource descriptor
1267 * @start: resource start address
1268 * @n: resource region size
1269 * @name: reserving caller's ID string
1270 * @flags: IO resource flags
1272 struct resource
*__request_region(struct resource
*parent
,
1273 resource_size_t start
, resource_size_t n
,
1274 const char *name
, int flags
)
1276 struct resource
*res
= alloc_resource(GFP_KERNEL
);
1282 write_lock(&resource_lock
);
1283 ret
= __request_region_locked(res
, parent
, start
, n
, name
, flags
);
1284 write_unlock(&resource_lock
);
1291 if (parent
== &iomem_resource
)
1296 EXPORT_SYMBOL(__request_region
);
1299 * __release_region - release a previously reserved resource region
1300 * @parent: parent resource descriptor
1301 * @start: resource start address
1302 * @n: resource region size
1304 * The described resource region must match a currently busy region.
1306 void __release_region(struct resource
*parent
, resource_size_t start
,
1309 struct resource
**p
;
1310 resource_size_t end
;
1313 end
= start
+ n
- 1;
1315 write_lock(&resource_lock
);
1318 struct resource
*res
= *p
;
1322 if (res
->start
<= start
&& res
->end
>= end
) {
1323 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1327 if (res
->start
!= start
|| res
->end
!= end
)
1330 write_unlock(&resource_lock
);
1331 if (res
->flags
& IORESOURCE_MUXED
)
1332 wake_up(&muxed_resource_wait
);
1339 write_unlock(&resource_lock
);
1341 pr_warn("Trying to free nonexistent resource <%pa-%pa>\n", &start
, &end
);
1343 EXPORT_SYMBOL(__release_region
);
1345 #ifdef CONFIG_MEMORY_HOTREMOVE
1347 * release_mem_region_adjustable - release a previously reserved memory region
1348 * @start: resource start address
1349 * @size: resource region size
1351 * This interface is intended for memory hot-delete. The requested region
1352 * is released from a currently busy memory resource. The requested region
1353 * must either match exactly or fit into a single busy resource entry. In
1354 * the latter case, the remaining resource is adjusted accordingly.
1355 * Existing children of the busy memory resource must be immutable in the
1359 * - Additional release conditions, such as overlapping region, can be
1360 * supported after they are confirmed as valid cases.
1361 * - When a busy memory resource gets split into two entries, the code
1362 * assumes that all children remain in the lower address entry for
1363 * simplicity. Enhance this logic when necessary.
1365 void release_mem_region_adjustable(resource_size_t start
, resource_size_t size
)
1367 struct resource
*parent
= &iomem_resource
;
1368 struct resource
*new_res
= NULL
;
1369 bool alloc_nofail
= false;
1370 struct resource
**p
;
1371 struct resource
*res
;
1372 resource_size_t end
;
1374 end
= start
+ size
- 1;
1375 if (WARN_ON_ONCE((start
< parent
->start
) || (end
> parent
->end
)))
1379 * We free up quite a lot of memory on memory hotunplug (esp., memap),
1380 * just before releasing the region. This is highly unlikely to
1381 * fail - let's play save and make it never fail as the caller cannot
1382 * perform any error handling (e.g., trying to re-add memory will fail
1386 new_res
= alloc_resource(GFP_KERNEL
| (alloc_nofail
? __GFP_NOFAIL
: 0));
1389 write_lock(&resource_lock
);
1391 while ((res
= *p
)) {
1392 if (res
->start
>= end
)
1395 /* look for the next resource if it does not fit into */
1396 if (res
->start
> start
|| res
->end
< end
) {
1401 if (!(res
->flags
& IORESOURCE_MEM
))
1404 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1409 /* found the target resource; let's adjust accordingly */
1410 if (res
->start
== start
&& res
->end
== end
) {
1411 /* free the whole entry */
1414 } else if (res
->start
== start
&& res
->end
!= end
) {
1415 /* adjust the start */
1416 WARN_ON_ONCE(__adjust_resource(res
, end
+ 1,
1418 } else if (res
->start
!= start
&& res
->end
== end
) {
1419 /* adjust the end */
1420 WARN_ON_ONCE(__adjust_resource(res
, res
->start
,
1421 start
- res
->start
));
1423 /* split into two entries - we need a new resource */
1425 new_res
= alloc_resource(GFP_ATOMIC
);
1427 alloc_nofail
= true;
1428 write_unlock(&resource_lock
);
1432 new_res
->name
= res
->name
;
1433 new_res
->start
= end
+ 1;
1434 new_res
->end
= res
->end
;
1435 new_res
->flags
= res
->flags
;
1436 new_res
->desc
= res
->desc
;
1437 new_res
->parent
= res
->parent
;
1438 new_res
->sibling
= res
->sibling
;
1439 new_res
->child
= NULL
;
1441 if (WARN_ON_ONCE(__adjust_resource(res
, res
->start
,
1442 start
- res
->start
)))
1444 res
->sibling
= new_res
;
1451 write_unlock(&resource_lock
);
1452 free_resource(new_res
);
1454 #endif /* CONFIG_MEMORY_HOTREMOVE */
1456 #ifdef CONFIG_MEMORY_HOTPLUG
1457 static bool system_ram_resources_mergeable(struct resource
*r1
,
1458 struct resource
*r2
)
1460 /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1461 return r1
->flags
== r2
->flags
&& r1
->end
+ 1 == r2
->start
&&
1462 r1
->name
== r2
->name
&& r1
->desc
== r2
->desc
&&
1463 !r1
->child
&& !r2
->child
;
1467 * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1468 * merge it with adjacent, mergeable resources
1469 * @res: resource descriptor
1471 * This interface is intended for memory hotplug, whereby lots of contiguous
1472 * system ram resources are added (e.g., via add_memory*()) by a driver, and
1473 * the actual resource boundaries are not of interest (e.g., it might be
1474 * relevant for DIMMs). Only resources that are marked mergeable, that have the
1475 * same parent, and that don't have any children are considered. All mergeable
1476 * resources must be immutable during the request.
1479 * - The caller has to make sure that no pointers to resources that are
1480 * marked mergeable are used anymore after this call - the resource might
1481 * be freed and the pointer might be stale!
1482 * - release_mem_region_adjustable() will split on demand on memory hotunplug
1484 void merge_system_ram_resource(struct resource
*res
)
1486 const unsigned long flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
1487 struct resource
*cur
;
1489 if (WARN_ON_ONCE((res
->flags
& flags
) != flags
))
1492 write_lock(&resource_lock
);
1493 res
->flags
|= IORESOURCE_SYSRAM_MERGEABLE
;
1495 /* Try to merge with next item in the list. */
1497 if (cur
&& system_ram_resources_mergeable(res
, cur
)) {
1498 res
->end
= cur
->end
;
1499 res
->sibling
= cur
->sibling
;
1503 /* Try to merge with previous item in the list. */
1504 cur
= res
->parent
->child
;
1505 while (cur
&& cur
->sibling
!= res
)
1507 if (cur
&& system_ram_resources_mergeable(cur
, res
)) {
1508 cur
->end
= res
->end
;
1509 cur
->sibling
= res
->sibling
;
1512 write_unlock(&resource_lock
);
1514 #endif /* CONFIG_MEMORY_HOTPLUG */
1517 * Managed region resource
1519 static void devm_resource_release(struct device
*dev
, void *ptr
)
1521 struct resource
**r
= ptr
;
1523 release_resource(*r
);
1527 * devm_request_resource() - request and reserve an I/O or memory resource
1528 * @dev: device for which to request the resource
1529 * @root: root of the resource tree from which to request the resource
1530 * @new: descriptor of the resource to request
1532 * This is a device-managed version of request_resource(). There is usually
1533 * no need to release resources requested by this function explicitly since
1534 * that will be taken care of when the device is unbound from its driver.
1535 * If for some reason the resource needs to be released explicitly, because
1536 * of ordering issues for example, drivers must call devm_release_resource()
1537 * rather than the regular release_resource().
1539 * When a conflict is detected between any existing resources and the newly
1540 * requested resource, an error message will be printed.
1542 * Returns 0 on success or a negative error code on failure.
1544 int devm_request_resource(struct device
*dev
, struct resource
*root
,
1545 struct resource
*new)
1547 struct resource
*conflict
, **ptr
;
1549 ptr
= devres_alloc(devm_resource_release
, sizeof(*ptr
), GFP_KERNEL
);
1555 conflict
= request_resource_conflict(root
, new);
1557 dev_err(dev
, "resource collision: %pR conflicts with %s %pR\n",
1558 new, conflict
->name
, conflict
);
1563 devres_add(dev
, ptr
);
1566 EXPORT_SYMBOL(devm_request_resource
);
1568 static int devm_resource_match(struct device
*dev
, void *res
, void *data
)
1570 struct resource
**ptr
= res
;
1572 return *ptr
== data
;
1576 * devm_release_resource() - release a previously requested resource
1577 * @dev: device for which to release the resource
1578 * @new: descriptor of the resource to release
1580 * Releases a resource previously requested using devm_request_resource().
1582 void devm_release_resource(struct device
*dev
, struct resource
*new)
1584 WARN_ON(devres_release(dev
, devm_resource_release
, devm_resource_match
,
1587 EXPORT_SYMBOL(devm_release_resource
);
1589 struct region_devres
{
1590 struct resource
*parent
;
1591 resource_size_t start
;
1595 static void devm_region_release(struct device
*dev
, void *res
)
1597 struct region_devres
*this = res
;
1599 __release_region(this->parent
, this->start
, this->n
);
1602 static int devm_region_match(struct device
*dev
, void *res
, void *match_data
)
1604 struct region_devres
*this = res
, *match
= match_data
;
1606 return this->parent
== match
->parent
&&
1607 this->start
== match
->start
&& this->n
== match
->n
;
1611 __devm_request_region(struct device
*dev
, struct resource
*parent
,
1612 resource_size_t start
, resource_size_t n
, const char *name
)
1614 struct region_devres
*dr
= NULL
;
1615 struct resource
*res
;
1617 dr
= devres_alloc(devm_region_release
, sizeof(struct region_devres
),
1622 dr
->parent
= parent
;
1626 res
= __request_region(parent
, start
, n
, name
, 0);
1628 devres_add(dev
, dr
);
1634 EXPORT_SYMBOL(__devm_request_region
);
1636 void __devm_release_region(struct device
*dev
, struct resource
*parent
,
1637 resource_size_t start
, resource_size_t n
)
1639 struct region_devres match_data
= { parent
, start
, n
};
1641 __release_region(parent
, start
, n
);
1642 WARN_ON(devres_destroy(dev
, devm_region_release
, devm_region_match
,
1645 EXPORT_SYMBOL(__devm_release_region
);
1648 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1650 #define MAXRESERVE 4
1651 static int __init
reserve_setup(char *str
)
1653 static int reserved
;
1654 static struct resource reserve
[MAXRESERVE
];
1657 unsigned int io_start
, io_num
;
1659 struct resource
*parent
;
1661 if (get_option(&str
, &io_start
) != 2)
1663 if (get_option(&str
, &io_num
) == 0)
1665 if (x
< MAXRESERVE
) {
1666 struct resource
*res
= reserve
+ x
;
1669 * If the region starts below 0x10000, we assume it's
1670 * I/O port space; otherwise assume it's memory.
1672 if (io_start
< 0x10000) {
1673 res
->flags
= IORESOURCE_IO
;
1674 parent
= &ioport_resource
;
1676 res
->flags
= IORESOURCE_MEM
;
1677 parent
= &iomem_resource
;
1679 res
->name
= "reserved";
1680 res
->start
= io_start
;
1681 res
->end
= io_start
+ io_num
- 1;
1682 res
->flags
|= IORESOURCE_BUSY
;
1683 res
->desc
= IORES_DESC_NONE
;
1685 if (request_resource(parent
, res
) == 0)
1691 __setup("reserve=", reserve_setup
);
1694 * Check if the requested addr and size spans more than any slot in the
1695 * iomem resource tree.
1697 int iomem_map_sanity_check(resource_size_t addr
, unsigned long size
)
1699 resource_size_t end
= addr
+ size
- 1;
1703 read_lock(&resource_lock
);
1704 for_each_resource(&iomem_resource
, p
, false) {
1706 * We can probably skip the resources without
1707 * IORESOURCE_IO attribute?
1713 if (PFN_DOWN(p
->start
) <= PFN_DOWN(addr
) &&
1714 PFN_DOWN(p
->end
) >= PFN_DOWN(end
))
1717 * if a resource is "BUSY", it's not a hardware resource
1718 * but a driver mapping of such a resource; we don't want
1719 * to warn for those; some drivers legitimately map only
1720 * partial hardware resources. (example: vesafb)
1722 if (p
->flags
& IORESOURCE_BUSY
)
1725 pr_warn("resource sanity check: requesting [mem %pa-%pa], which spans more than %s %pR\n",
1726 &addr
, &end
, p
->name
, p
);
1730 read_unlock(&resource_lock
);
1735 #ifdef CONFIG_STRICT_DEVMEM
1736 static int strict_iomem_checks
= 1;
1738 static int strict_iomem_checks
;
1742 * Check if an address is exclusive to the kernel and must not be mapped to
1743 * user space, for example, via /dev/mem.
1745 * Returns true if exclusive to the kernel, otherwise returns false.
1747 bool resource_is_exclusive(struct resource
*root
, u64 addr
, resource_size_t size
)
1749 const unsigned int exclusive_system_ram
= IORESOURCE_SYSTEM_RAM
|
1750 IORESOURCE_EXCLUSIVE
;
1751 bool skip_children
= false, err
= false;
1754 read_lock(&resource_lock
);
1755 for_each_resource(root
, p
, skip_children
) {
1756 if (p
->start
>= addr
+ size
)
1758 if (p
->end
< addr
) {
1759 skip_children
= true;
1762 skip_children
= false;
1765 * IORESOURCE_SYSTEM_RAM resources are exclusive if
1766 * IORESOURCE_EXCLUSIVE is set, even if they
1767 * are not busy and even if "iomem=relaxed" is set. The
1768 * responsible driver dynamically adds/removes system RAM within
1769 * such an area and uncontrolled access is dangerous.
1771 if ((p
->flags
& exclusive_system_ram
) == exclusive_system_ram
) {
1777 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1778 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1781 if (!strict_iomem_checks
|| !(p
->flags
& IORESOURCE_BUSY
))
1783 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM
)
1784 || p
->flags
& IORESOURCE_EXCLUSIVE
) {
1789 read_unlock(&resource_lock
);
1794 bool iomem_is_exclusive(u64 addr
)
1796 return resource_is_exclusive(&iomem_resource
, addr
& PAGE_MASK
,
1800 struct resource_entry
*resource_list_create_entry(struct resource
*res
,
1803 struct resource_entry
*entry
;
1805 entry
= kzalloc(sizeof(*entry
) + extra_size
, GFP_KERNEL
);
1807 INIT_LIST_HEAD(&entry
->node
);
1808 entry
->res
= res
? res
: &entry
->__res
;
1813 EXPORT_SYMBOL(resource_list_create_entry
);
1815 void resource_list_free(struct list_head
*head
)
1817 struct resource_entry
*entry
, *tmp
;
1819 list_for_each_entry_safe(entry
, tmp
, head
, node
)
1820 resource_list_destroy_entry(entry
);
1822 EXPORT_SYMBOL(resource_list_free
);
1824 #ifdef CONFIG_GET_FREE_REGION
1825 #define GFR_DESCENDING (1UL << 0)
1826 #define GFR_REQUEST_REGION (1UL << 1)
1827 #define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT)
1829 static resource_size_t
gfr_start(struct resource
*base
, resource_size_t size
,
1830 resource_size_t align
, unsigned long flags
)
1832 if (flags
& GFR_DESCENDING
) {
1833 resource_size_t end
;
1835 end
= min_t(resource_size_t
, base
->end
,
1836 (1ULL << MAX_PHYSMEM_BITS
) - 1);
1837 return end
- size
+ 1;
1840 return ALIGN(base
->start
, align
);
1843 static bool gfr_continue(struct resource
*base
, resource_size_t addr
,
1844 resource_size_t size
, unsigned long flags
)
1846 if (flags
& GFR_DESCENDING
)
1847 return addr
> size
&& addr
>= base
->start
;
1849 * In the ascend case be careful that the last increment by
1850 * @size did not wrap 0.
1852 return addr
> addr
- size
&&
1853 addr
<= min_t(resource_size_t
, base
->end
,
1854 (1ULL << MAX_PHYSMEM_BITS
) - 1);
1857 static resource_size_t
gfr_next(resource_size_t addr
, resource_size_t size
,
1858 unsigned long flags
)
1860 if (flags
& GFR_DESCENDING
)
1865 static void remove_free_mem_region(void *_res
)
1867 struct resource
*res
= _res
;
1870 remove_resource(res
);
1874 static struct resource
*
1875 get_free_mem_region(struct device
*dev
, struct resource
*base
,
1876 resource_size_t size
, const unsigned long align
,
1877 const char *name
, const unsigned long desc
,
1878 const unsigned long flags
)
1880 resource_size_t addr
;
1881 struct resource
*res
;
1882 struct region_devres
*dr
= NULL
;
1884 size
= ALIGN(size
, align
);
1886 res
= alloc_resource(GFP_KERNEL
);
1888 return ERR_PTR(-ENOMEM
);
1890 if (dev
&& (flags
& GFR_REQUEST_REGION
)) {
1891 dr
= devres_alloc(devm_region_release
,
1892 sizeof(struct region_devres
), GFP_KERNEL
);
1895 return ERR_PTR(-ENOMEM
);
1898 if (devm_add_action_or_reset(dev
, remove_free_mem_region
, res
))
1899 return ERR_PTR(-ENOMEM
);
1902 write_lock(&resource_lock
);
1903 for (addr
= gfr_start(base
, size
, align
, flags
);
1904 gfr_continue(base
, addr
, align
, flags
);
1905 addr
= gfr_next(addr
, align
, flags
)) {
1906 if (__region_intersects(base
, addr
, size
, 0, IORES_DESC_NONE
) !=
1910 if (flags
& GFR_REQUEST_REGION
) {
1911 if (__request_region_locked(res
, &iomem_resource
, addr
,
1916 dr
->parent
= &iomem_resource
;
1919 devres_add(dev
, dr
);
1923 write_unlock(&resource_lock
);
1927 * A driver is claiming this region so revoke any
1933 res
->end
= addr
+ size
- 1;
1936 res
->flags
= IORESOURCE_MEM
;
1939 * Only succeed if the resource hosts an exclusive
1940 * range after the insert
1942 if (__insert_resource(base
, res
) || res
->child
)
1945 write_unlock(&resource_lock
);
1950 write_unlock(&resource_lock
);
1952 if (flags
& GFR_REQUEST_REGION
) {
1956 devm_release_action(dev
, remove_free_mem_region
, res
);
1958 return ERR_PTR(-ERANGE
);
1962 * devm_request_free_mem_region - find free region for device private memory
1964 * @dev: device struct to bind the resource to
1965 * @size: size in bytes of the device memory to add
1966 * @base: resource tree to look in
1968 * This function tries to find an empty range of physical address big enough to
1969 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1970 * memory, which in turn allocates struct pages.
1972 struct resource
*devm_request_free_mem_region(struct device
*dev
,
1973 struct resource
*base
, unsigned long size
)
1975 unsigned long flags
= GFR_DESCENDING
| GFR_REQUEST_REGION
;
1977 return get_free_mem_region(dev
, base
, size
, GFR_DEFAULT_ALIGN
,
1979 IORES_DESC_DEVICE_PRIVATE_MEMORY
, flags
);
1981 EXPORT_SYMBOL_GPL(devm_request_free_mem_region
);
1983 struct resource
*request_free_mem_region(struct resource
*base
,
1984 unsigned long size
, const char *name
)
1986 unsigned long flags
= GFR_DESCENDING
| GFR_REQUEST_REGION
;
1988 return get_free_mem_region(NULL
, base
, size
, GFR_DEFAULT_ALIGN
, name
,
1989 IORES_DESC_DEVICE_PRIVATE_MEMORY
, flags
);
1991 EXPORT_SYMBOL_GPL(request_free_mem_region
);
1994 * alloc_free_mem_region - find a free region relative to @base
1995 * @base: resource that will parent the new resource
1996 * @size: size in bytes of memory to allocate from @base
1997 * @align: alignment requirements for the allocation
1998 * @name: resource name
2000 * Buses like CXL, that can dynamically instantiate new memory regions,
2001 * need a method to allocate physical address space for those regions.
2002 * Allocate and insert a new resource to cover a free, unclaimed by a
2003 * descendant of @base, range in the span of @base.
2005 struct resource
*alloc_free_mem_region(struct resource
*base
,
2006 unsigned long size
, unsigned long align
,
2009 /* Default of ascending direction and insert resource */
2010 unsigned long flags
= 0;
2012 return get_free_mem_region(NULL
, base
, size
, align
, name
,
2013 IORES_DESC_NONE
, flags
);
2015 EXPORT_SYMBOL_NS_GPL(alloc_free_mem_region
, CXL
);
2016 #endif /* CONFIG_GET_FREE_REGION */
2018 static int __init
strict_iomem(char *str
)
2020 if (strstr(str
, "relaxed"))
2021 strict_iomem_checks
= 0;
2022 if (strstr(str
, "strict"))
2023 strict_iomem_checks
= 1;
2027 static int iomem_fs_init_fs_context(struct fs_context
*fc
)
2029 return init_pseudo(fc
, DEVMEM_MAGIC
) ? 0 : -ENOMEM
;
2032 static struct file_system_type iomem_fs_type
= {
2034 .owner
= THIS_MODULE
,
2035 .init_fs_context
= iomem_fs_init_fs_context
,
2036 .kill_sb
= kill_anon_super
,
2039 static int __init
iomem_init_inode(void)
2041 static struct vfsmount
*iomem_vfs_mount
;
2042 static int iomem_fs_cnt
;
2043 struct inode
*inode
;
2046 rc
= simple_pin_fs(&iomem_fs_type
, &iomem_vfs_mount
, &iomem_fs_cnt
);
2048 pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc
);
2052 inode
= alloc_anon_inode(iomem_vfs_mount
->mnt_sb
);
2053 if (IS_ERR(inode
)) {
2054 rc
= PTR_ERR(inode
);
2055 pr_err("Cannot allocate inode for iomem: %d\n", rc
);
2056 simple_release_fs(&iomem_vfs_mount
, &iomem_fs_cnt
);
2061 * Publish iomem revocation inode initialized.
2062 * Pairs with smp_load_acquire() in revoke_iomem().
2064 smp_store_release(&iomem_inode
, inode
);
2069 fs_initcall(iomem_init_inode
);
2071 __setup("iomem=", strict_iomem
);