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
);
60 * For memory hotplug, there is no way to free resource entries allocated
61 * by boot mem after the system is up. So for reusing the resource entry
62 * we need to remember the resource.
64 static struct resource
*bootmem_resource_free
;
65 static DEFINE_SPINLOCK(bootmem_resource_lock
);
67 static struct resource
*next_resource(struct resource
*p
)
71 while (!p
->sibling
&& p
->parent
)
76 static void *r_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
78 struct resource
*p
= v
;
80 return (void *)next_resource(p
);
85 enum { MAX_IORES_LEVEL
= 5 };
87 static void *r_start(struct seq_file
*m
, loff_t
*pos
)
88 __acquires(resource_lock
)
90 struct resource
*p
= PDE_DATA(file_inode(m
->file
));
92 read_lock(&resource_lock
);
93 for (p
= p
->child
; p
&& l
< *pos
; p
= r_next(m
, p
, &l
))
98 static void r_stop(struct seq_file
*m
, void *v
)
99 __releases(resource_lock
)
101 read_unlock(&resource_lock
);
104 static int r_show(struct seq_file
*m
, void *v
)
106 struct resource
*root
= PDE_DATA(file_inode(m
->file
));
107 struct resource
*r
= v
, *p
;
108 unsigned long long start
, end
;
109 int width
= root
->end
< 0x10000 ? 4 : 8;
112 for (depth
= 0, p
= r
; depth
< MAX_IORES_LEVEL
; depth
++, p
= p
->parent
)
113 if (p
->parent
== root
)
116 if (file_ns_capable(m
->file
, &init_user_ns
, CAP_SYS_ADMIN
)) {
123 seq_printf(m
, "%*s%0*llx-%0*llx : %s\n",
127 r
->name
? r
->name
: "<BAD>");
131 static const struct seq_operations resource_op
= {
138 static int __init
ioresources_init(void)
140 proc_create_seq_data("ioports", 0, NULL
, &resource_op
,
142 proc_create_seq_data("iomem", 0, NULL
, &resource_op
, &iomem_resource
);
145 __initcall(ioresources_init
);
147 #endif /* CONFIG_PROC_FS */
149 static void free_resource(struct resource
*res
)
154 if (!PageSlab(virt_to_head_page(res
))) {
155 spin_lock(&bootmem_resource_lock
);
156 res
->sibling
= bootmem_resource_free
;
157 bootmem_resource_free
= res
;
158 spin_unlock(&bootmem_resource_lock
);
164 static struct resource
*alloc_resource(gfp_t flags
)
166 struct resource
*res
= NULL
;
168 spin_lock(&bootmem_resource_lock
);
169 if (bootmem_resource_free
) {
170 res
= bootmem_resource_free
;
171 bootmem_resource_free
= res
->sibling
;
173 spin_unlock(&bootmem_resource_lock
);
176 memset(res
, 0, sizeof(struct resource
));
178 res
= kzalloc(sizeof(struct resource
), flags
);
183 /* Return the conflict entry if you can't request it */
184 static struct resource
* __request_resource(struct resource
*root
, struct resource
*new)
186 resource_size_t start
= new->start
;
187 resource_size_t end
= new->end
;
188 struct resource
*tmp
, **p
;
192 if (start
< root
->start
)
199 if (!tmp
|| tmp
->start
> end
) {
206 if (tmp
->end
< start
)
212 static int __release_resource(struct resource
*old
, bool release_child
)
214 struct resource
*tmp
, **p
, *chd
;
216 p
= &old
->parent
->child
;
222 if (release_child
|| !(tmp
->child
)) {
225 for (chd
= tmp
->child
;; chd
= chd
->sibling
) {
226 chd
->parent
= tmp
->parent
;
231 chd
->sibling
= tmp
->sibling
;
241 static void __release_child_resources(struct resource
*r
)
243 struct resource
*tmp
, *p
;
244 resource_size_t size
;
254 __release_child_resources(tmp
);
256 printk(KERN_DEBUG
"release child resource %pR\n", tmp
);
257 /* need to restore size, and keep flags */
258 size
= resource_size(tmp
);
264 void release_child_resources(struct resource
*r
)
266 write_lock(&resource_lock
);
267 __release_child_resources(r
);
268 write_unlock(&resource_lock
);
272 * request_resource_conflict - request and reserve an I/O or memory resource
273 * @root: root resource descriptor
274 * @new: resource descriptor desired by caller
276 * Returns 0 for success, conflict resource on error.
278 struct resource
*request_resource_conflict(struct resource
*root
, struct resource
*new)
280 struct resource
*conflict
;
282 write_lock(&resource_lock
);
283 conflict
= __request_resource(root
, new);
284 write_unlock(&resource_lock
);
289 * request_resource - request and reserve an I/O or memory resource
290 * @root: root resource descriptor
291 * @new: resource descriptor desired by caller
293 * Returns 0 for success, negative error code on error.
295 int request_resource(struct resource
*root
, struct resource
*new)
297 struct resource
*conflict
;
299 conflict
= request_resource_conflict(root
, new);
300 return conflict
? -EBUSY
: 0;
303 EXPORT_SYMBOL(request_resource
);
306 * release_resource - release a previously reserved resource
307 * @old: resource pointer
309 int release_resource(struct resource
*old
)
313 write_lock(&resource_lock
);
314 retval
= __release_resource(old
, true);
315 write_unlock(&resource_lock
);
319 EXPORT_SYMBOL(release_resource
);
322 * find_next_iomem_res - Finds the lowest iomem resource that covers part of
325 * If a resource is found, returns 0 and @*res is overwritten with the part
326 * of the resource that's within [@start..@end]; if none is found, returns
327 * -ENODEV. Returns -EINVAL for invalid parameters.
329 * @start: start address of the resource searched for
330 * @end: end address of same resource
331 * @flags: flags which the resource must have
332 * @desc: descriptor the resource must have
333 * @res: return ptr, if resource found
335 * The caller must specify @start, @end, @flags, and @desc
336 * (which may be IORES_DESC_NONE).
338 static int find_next_iomem_res(resource_size_t start
, resource_size_t end
,
339 unsigned long flags
, unsigned long desc
,
340 struct resource
*res
)
350 read_lock(&resource_lock
);
352 for (p
= iomem_resource
.child
; p
; p
= next_resource(p
)) {
353 /* If we passed the resource we are looking for, stop */
354 if (p
->start
> end
) {
359 /* Skip until we find a range that matches what we look for */
363 if ((p
->flags
& flags
) != flags
)
365 if ((desc
!= IORES_DESC_NONE
) && (desc
!= p
->desc
))
368 /* Found a match, break */
374 *res
= (struct resource
) {
375 .start
= max(start
, p
->start
),
376 .end
= min(end
, p
->end
),
383 read_unlock(&resource_lock
);
384 return p
? 0 : -ENODEV
;
387 static int __walk_iomem_res_desc(resource_size_t start
, resource_size_t end
,
388 unsigned long flags
, unsigned long desc
,
390 int (*func
)(struct resource
*, void *))
395 while (start
< end
&&
396 !find_next_iomem_res(start
, end
, flags
, desc
, &res
)) {
397 ret
= (*func
)(&res
, arg
);
408 * walk_iomem_res_desc - Walks through iomem resources and calls func()
409 * with matching resource ranges.
411 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
412 * @flags: I/O resource flags
415 * @arg: function argument for the callback @func
416 * @func: callback function that is called for each qualifying resource area
418 * All the memory ranges which overlap start,end and also match flags and
419 * desc are valid candidates.
421 * NOTE: For a new descriptor search, define a new IORES_DESC in
422 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
424 int walk_iomem_res_desc(unsigned long desc
, unsigned long flags
, u64 start
,
425 u64 end
, void *arg
, int (*func
)(struct resource
*, void *))
427 return __walk_iomem_res_desc(start
, end
, flags
, desc
, arg
, func
);
429 EXPORT_SYMBOL_GPL(walk_iomem_res_desc
);
432 * This function calls the @func callback against all memory ranges of type
433 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
434 * Now, this function is only for System RAM, it deals with full ranges and
435 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
438 int walk_system_ram_res(u64 start
, u64 end
, void *arg
,
439 int (*func
)(struct resource
*, void *))
441 unsigned long flags
= IORESOURCE_SYSTEM_RAM
| 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, which
449 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
451 int walk_mem_res(u64 start
, u64 end
, void *arg
,
452 int (*func
)(struct resource
*, void *))
454 unsigned long flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
456 return __walk_iomem_res_desc(start
, end
, flags
, IORES_DESC_NONE
, arg
,
461 * This function calls the @func callback against all memory ranges of type
462 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
463 * It is to be used only for System RAM.
465 int walk_system_ram_range(unsigned long start_pfn
, unsigned long nr_pages
,
466 void *arg
, int (*func
)(unsigned long, unsigned long, void *))
468 resource_size_t start
, end
;
471 unsigned long pfn
, end_pfn
;
474 start
= (u64
) start_pfn
<< PAGE_SHIFT
;
475 end
= ((u64
)(start_pfn
+ nr_pages
) << PAGE_SHIFT
) - 1;
476 flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
477 while (start
< end
&&
478 !find_next_iomem_res(start
, end
, flags
, IORES_DESC_NONE
, &res
)) {
479 pfn
= PFN_UP(res
.start
);
480 end_pfn
= PFN_DOWN(res
.end
+ 1);
482 ret
= (*func
)(pfn
, end_pfn
- pfn
, arg
);
490 static int __is_ram(unsigned long pfn
, unsigned long nr_pages
, void *arg
)
496 * This generic page_is_ram() returns true if specified address is
497 * registered as System RAM in iomem_resource list.
499 int __weak
page_is_ram(unsigned long pfn
)
501 return walk_system_ram_range(pfn
, 1, NULL
, __is_ram
) == 1;
503 EXPORT_SYMBOL_GPL(page_is_ram
);
506 * region_intersects() - determine intersection of region with known resources
507 * @start: region start address
508 * @size: size of region
509 * @flags: flags of resource (in iomem_resource)
510 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
512 * Check if the specified region partially overlaps or fully eclipses a
513 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
514 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
515 * return REGION_MIXED if the region overlaps @flags/@desc and another
516 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
517 * and no other defined resource. Note that REGION_INTERSECTS is also
518 * returned in the case when the specified region overlaps RAM and undefined
521 * region_intersect() is used by memory remapping functions to ensure
522 * the user is not remapping RAM and is a vast speed up over walking
523 * through the resource table page by page.
525 int region_intersects(resource_size_t start
, size_t size
, unsigned long flags
,
529 int type
= 0; int other
= 0;
533 res
.end
= start
+ size
- 1;
535 read_lock(&resource_lock
);
536 for (p
= iomem_resource
.child
; p
; p
= p
->sibling
) {
537 bool is_type
= (((p
->flags
& flags
) == flags
) &&
538 ((desc
== IORES_DESC_NONE
) ||
541 if (resource_overlaps(p
, &res
))
542 is_type
? type
++ : other
++;
544 read_unlock(&resource_lock
);
547 return REGION_DISJOINT
;
550 return REGION_INTERSECTS
;
554 EXPORT_SYMBOL_GPL(region_intersects
);
556 void __weak
arch_remove_reservations(struct resource
*avail
)
560 static resource_size_t
simple_align_resource(void *data
,
561 const struct resource
*avail
,
562 resource_size_t size
,
563 resource_size_t align
)
568 static void resource_clip(struct resource
*res
, resource_size_t min
,
571 if (res
->start
< min
)
578 * Find empty slot in the resource tree with the given range and
579 * alignment constraints
581 static int __find_resource(struct resource
*root
, struct resource
*old
,
582 struct resource
*new,
583 resource_size_t size
,
584 struct resource_constraint
*constraint
)
586 struct resource
*this = root
->child
;
587 struct resource tmp
= *new, avail
, alloc
;
589 tmp
.start
= root
->start
;
591 * Skip past an allocated resource that starts at 0, since the assignment
592 * of this->start - 1 to tmp->end below would cause an underflow.
594 if (this && this->start
== root
->start
) {
595 tmp
.start
= (this == old
) ? old
->start
: this->end
+ 1;
596 this = this->sibling
;
600 tmp
.end
= (this == old
) ? this->end
: this->start
- 1;
604 if (tmp
.end
< tmp
.start
)
607 resource_clip(&tmp
, constraint
->min
, constraint
->max
);
608 arch_remove_reservations(&tmp
);
610 /* Check for overflow after ALIGN() */
611 avail
.start
= ALIGN(tmp
.start
, constraint
->align
);
613 avail
.flags
= new->flags
& ~IORESOURCE_UNSET
;
614 if (avail
.start
>= tmp
.start
) {
615 alloc
.flags
= avail
.flags
;
616 alloc
.start
= constraint
->alignf(constraint
->alignf_data
, &avail
,
617 size
, constraint
->align
);
618 alloc
.end
= alloc
.start
+ size
- 1;
619 if (alloc
.start
<= alloc
.end
&&
620 resource_contains(&avail
, &alloc
)) {
621 new->start
= alloc
.start
;
622 new->end
= alloc
.end
;
627 next
: if (!this || this->end
== root
->end
)
631 tmp
.start
= this->end
+ 1;
632 this = this->sibling
;
638 * Find empty slot in the resource tree given range and alignment.
640 static int find_resource(struct resource
*root
, struct resource
*new,
641 resource_size_t size
,
642 struct resource_constraint
*constraint
)
644 return __find_resource(root
, NULL
, new, size
, constraint
);
648 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
649 * The resource will be relocated if the new size cannot be reallocated in the
652 * @root: root resource descriptor
653 * @old: resource descriptor desired by caller
654 * @newsize: new size of the resource descriptor
655 * @constraint: the size and alignment constraints to be met.
657 static int reallocate_resource(struct resource
*root
, struct resource
*old
,
658 resource_size_t newsize
,
659 struct resource_constraint
*constraint
)
662 struct resource
new = *old
;
663 struct resource
*conflict
;
665 write_lock(&resource_lock
);
667 if ((err
= __find_resource(root
, old
, &new, newsize
, constraint
)))
670 if (resource_contains(&new, old
)) {
671 old
->start
= new.start
;
681 if (resource_contains(old
, &new)) {
682 old
->start
= new.start
;
685 __release_resource(old
, true);
687 conflict
= __request_resource(root
, old
);
691 write_unlock(&resource_lock
);
697 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
698 * The resource will be reallocated with a new size if it was already allocated
699 * @root: root resource descriptor
700 * @new: resource descriptor desired by caller
701 * @size: requested resource region size
702 * @min: minimum boundary to allocate
703 * @max: maximum boundary to allocate
704 * @align: alignment requested, in bytes
705 * @alignf: alignment function, optional, called if not NULL
706 * @alignf_data: arbitrary data to pass to the @alignf function
708 int allocate_resource(struct resource
*root
, struct resource
*new,
709 resource_size_t size
, resource_size_t min
,
710 resource_size_t max
, resource_size_t align
,
711 resource_size_t (*alignf
)(void *,
712 const struct resource
*,
718 struct resource_constraint constraint
;
721 alignf
= simple_align_resource
;
723 constraint
.min
= min
;
724 constraint
.max
= max
;
725 constraint
.align
= align
;
726 constraint
.alignf
= alignf
;
727 constraint
.alignf_data
= alignf_data
;
730 /* resource is already allocated, try reallocating with
731 the new constraints */
732 return reallocate_resource(root
, new, size
, &constraint
);
735 write_lock(&resource_lock
);
736 err
= find_resource(root
, new, size
, &constraint
);
737 if (err
>= 0 && __request_resource(root
, new))
739 write_unlock(&resource_lock
);
743 EXPORT_SYMBOL(allocate_resource
);
746 * lookup_resource - find an existing resource by a resource start address
747 * @root: root resource descriptor
748 * @start: resource start address
750 * Returns a pointer to the resource if found, NULL otherwise
752 struct resource
*lookup_resource(struct resource
*root
, resource_size_t start
)
754 struct resource
*res
;
756 read_lock(&resource_lock
);
757 for (res
= root
->child
; res
; res
= res
->sibling
) {
758 if (res
->start
== start
)
761 read_unlock(&resource_lock
);
767 * Insert a resource into the resource tree. If successful, return NULL,
768 * otherwise return the conflicting resource (compare to __request_resource())
770 static struct resource
* __insert_resource(struct resource
*parent
, struct resource
*new)
772 struct resource
*first
, *next
;
774 for (;; parent
= first
) {
775 first
= __request_resource(parent
, new);
781 if (WARN_ON(first
== new)) /* duplicated insertion */
784 if ((first
->start
> new->start
) || (first
->end
< new->end
))
786 if ((first
->start
== new->start
) && (first
->end
== new->end
))
790 for (next
= first
; ; next
= next
->sibling
) {
791 /* Partial overlap? Bad, and unfixable */
792 if (next
->start
< new->start
|| next
->end
> new->end
)
796 if (next
->sibling
->start
> new->end
)
800 new->parent
= parent
;
801 new->sibling
= next
->sibling
;
804 next
->sibling
= NULL
;
805 for (next
= first
; next
; next
= next
->sibling
)
808 if (parent
->child
== first
) {
811 next
= parent
->child
;
812 while (next
->sibling
!= first
)
813 next
= next
->sibling
;
820 * insert_resource_conflict - Inserts resource in the resource tree
821 * @parent: parent of the new resource
822 * @new: new resource to insert
824 * Returns 0 on success, conflict resource if the resource can't be inserted.
826 * This function is equivalent to request_resource_conflict when no conflict
827 * happens. If a conflict happens, and the conflicting resources
828 * entirely fit within the range of the new resource, then the new
829 * resource is inserted and the conflicting resources become children of
832 * This function is intended for producers of resources, such as FW modules
835 struct resource
*insert_resource_conflict(struct resource
*parent
, struct resource
*new)
837 struct resource
*conflict
;
839 write_lock(&resource_lock
);
840 conflict
= __insert_resource(parent
, new);
841 write_unlock(&resource_lock
);
846 * insert_resource - Inserts a resource in the resource tree
847 * @parent: parent of the new resource
848 * @new: new resource to insert
850 * Returns 0 on success, -EBUSY if the resource can't be inserted.
852 * This function is intended for producers of resources, such as FW modules
855 int insert_resource(struct resource
*parent
, struct resource
*new)
857 struct resource
*conflict
;
859 conflict
= insert_resource_conflict(parent
, new);
860 return conflict
? -EBUSY
: 0;
862 EXPORT_SYMBOL_GPL(insert_resource
);
865 * insert_resource_expand_to_fit - Insert a resource into the resource tree
866 * @root: root resource descriptor
867 * @new: new resource to insert
869 * Insert a resource into the resource tree, possibly expanding it in order
870 * to make it encompass any conflicting resources.
872 void insert_resource_expand_to_fit(struct resource
*root
, struct resource
*new)
877 write_lock(&resource_lock
);
879 struct resource
*conflict
;
881 conflict
= __insert_resource(root
, new);
884 if (conflict
== root
)
887 /* Ok, expand resource to cover the conflict, then try again .. */
888 if (conflict
->start
< new->start
)
889 new->start
= conflict
->start
;
890 if (conflict
->end
> new->end
)
891 new->end
= conflict
->end
;
893 printk("Expanded resource %s due to conflict with %s\n", new->name
, conflict
->name
);
895 write_unlock(&resource_lock
);
899 * remove_resource - Remove a resource in the resource tree
900 * @old: resource to remove
902 * Returns 0 on success, -EINVAL if the resource is not valid.
904 * This function removes a resource previously inserted by insert_resource()
905 * or insert_resource_conflict(), and moves the children (if any) up to
906 * where they were before. insert_resource() and insert_resource_conflict()
907 * insert a new resource, and move any conflicting resources down to the
908 * children of the new resource.
910 * insert_resource(), insert_resource_conflict() and remove_resource() are
911 * intended for producers of resources, such as FW modules and bus drivers.
913 int remove_resource(struct resource
*old
)
917 write_lock(&resource_lock
);
918 retval
= __release_resource(old
, false);
919 write_unlock(&resource_lock
);
922 EXPORT_SYMBOL_GPL(remove_resource
);
924 static int __adjust_resource(struct resource
*res
, resource_size_t start
,
925 resource_size_t size
)
927 struct resource
*tmp
, *parent
= res
->parent
;
928 resource_size_t end
= start
+ size
- 1;
934 if ((start
< parent
->start
) || (end
> parent
->end
))
937 if (res
->sibling
&& (res
->sibling
->start
<= end
))
942 while (tmp
->sibling
!= res
)
944 if (start
<= tmp
->end
)
949 for (tmp
= res
->child
; tmp
; tmp
= tmp
->sibling
)
950 if ((tmp
->start
< start
) || (tmp
->end
> end
))
962 * adjust_resource - modify a resource's start and size
963 * @res: resource to modify
964 * @start: new start value
967 * Given an existing resource, change its start and size to match the
968 * arguments. Returns 0 on success, -EBUSY if it can't fit.
969 * Existing children of the resource are assumed to be immutable.
971 int adjust_resource(struct resource
*res
, resource_size_t start
,
972 resource_size_t size
)
976 write_lock(&resource_lock
);
977 result
= __adjust_resource(res
, start
, size
);
978 write_unlock(&resource_lock
);
981 EXPORT_SYMBOL(adjust_resource
);
984 __reserve_region_with_split(struct resource
*root
, resource_size_t start
,
985 resource_size_t end
, const char *name
)
987 struct resource
*parent
= root
;
988 struct resource
*conflict
;
989 struct resource
*res
= alloc_resource(GFP_ATOMIC
);
990 struct resource
*next_res
= NULL
;
991 int type
= resource_type(root
);
999 res
->flags
= type
| IORESOURCE_BUSY
;
1000 res
->desc
= IORES_DESC_NONE
;
1004 conflict
= __request_resource(parent
, res
);
1013 /* conflict covered whole area */
1014 if (conflict
->start
<= res
->start
&&
1015 conflict
->end
>= res
->end
) {
1021 /* failed, split and try again */
1022 if (conflict
->start
> res
->start
) {
1024 res
->end
= conflict
->start
- 1;
1025 if (conflict
->end
< end
) {
1026 next_res
= alloc_resource(GFP_ATOMIC
);
1031 next_res
->name
= name
;
1032 next_res
->start
= conflict
->end
+ 1;
1033 next_res
->end
= end
;
1034 next_res
->flags
= type
| IORESOURCE_BUSY
;
1035 next_res
->desc
= IORES_DESC_NONE
;
1038 res
->start
= conflict
->end
+ 1;
1045 reserve_region_with_split(struct resource
*root
, resource_size_t start
,
1046 resource_size_t end
, const char *name
)
1050 write_lock(&resource_lock
);
1051 if (root
->start
> start
|| root
->end
< end
) {
1052 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1053 (unsigned long long)start
, (unsigned long long)end
,
1055 if (start
> root
->end
|| end
< root
->start
)
1058 if (end
> root
->end
)
1060 if (start
< root
->start
)
1061 start
= root
->start
;
1062 pr_err("fixing request to [0x%llx-0x%llx]\n",
1063 (unsigned long long)start
,
1064 (unsigned long long)end
);
1069 __reserve_region_with_split(root
, start
, end
, name
);
1070 write_unlock(&resource_lock
);
1074 * resource_alignment - calculate resource's alignment
1075 * @res: resource pointer
1077 * Returns alignment on success, 0 (invalid alignment) on failure.
1079 resource_size_t
resource_alignment(struct resource
*res
)
1081 switch (res
->flags
& (IORESOURCE_SIZEALIGN
| IORESOURCE_STARTALIGN
)) {
1082 case IORESOURCE_SIZEALIGN
:
1083 return resource_size(res
);
1084 case IORESOURCE_STARTALIGN
:
1092 * This is compatibility stuff for IO resources.
1094 * Note how this, unlike the above, knows about
1095 * the IO flag meanings (busy etc).
1097 * request_region creates a new busy region.
1099 * release_region releases a matching busy region.
1102 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait
);
1104 static struct inode
*iomem_inode
;
1106 #ifdef CONFIG_IO_STRICT_DEVMEM
1107 static void revoke_iomem(struct resource
*res
)
1109 /* pairs with smp_store_release() in iomem_init_inode() */
1110 struct inode
*inode
= smp_load_acquire(&iomem_inode
);
1113 * Check that the initialization has completed. Losing the race
1114 * is ok because it means drivers are claiming resources before
1115 * the fs_initcall level of init and prevent iomem_get_mapping users
1116 * from establishing mappings.
1122 * The expectation is that the driver has successfully marked
1123 * the resource busy by this point, so devmem_is_allowed()
1124 * should start returning false, however for performance this
1125 * does not iterate the entire resource range.
1127 if (devmem_is_allowed(PHYS_PFN(res
->start
)) &&
1128 devmem_is_allowed(PHYS_PFN(res
->end
))) {
1130 * *cringe* iomem=relaxed says "go ahead, what's the
1131 * worst that can happen?"
1136 unmap_mapping_range(inode
->i_mapping
, res
->start
, resource_size(res
), 1);
1139 static void revoke_iomem(struct resource
*res
) {}
1142 struct address_space
*iomem_get_mapping(void)
1145 * This function is only called from file open paths, hence guaranteed
1146 * that fs_initcalls have completed and no need to check for NULL. But
1147 * since revoke_iomem can be called before the initcall we still need
1148 * the barrier to appease checkers.
1150 return smp_load_acquire(&iomem_inode
)->i_mapping
;
1154 * __request_region - create a new busy resource region
1155 * @parent: parent resource descriptor
1156 * @start: resource start address
1157 * @n: resource region size
1158 * @name: reserving caller's ID string
1159 * @flags: IO resource flags
1161 struct resource
* __request_region(struct resource
*parent
,
1162 resource_size_t start
, resource_size_t n
,
1163 const char *name
, int flags
)
1165 DECLARE_WAITQUEUE(wait
, current
);
1166 struct resource
*res
= alloc_resource(GFP_KERNEL
);
1167 struct resource
*orig_parent
= parent
;
1174 res
->end
= start
+ n
- 1;
1176 write_lock(&resource_lock
);
1179 struct resource
*conflict
;
1181 res
->flags
= resource_type(parent
) | resource_ext_type(parent
);
1182 res
->flags
|= IORESOURCE_BUSY
| flags
;
1183 res
->desc
= parent
->desc
;
1185 conflict
= __request_resource(parent
, res
);
1189 * mm/hmm.c reserves physical addresses which then
1190 * become unavailable to other users. Conflicts are
1191 * not expected. Warn to aid debugging if encountered.
1193 if (conflict
->desc
== IORES_DESC_DEVICE_PRIVATE_MEMORY
) {
1194 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1195 conflict
->name
, conflict
, res
);
1197 if (conflict
!= parent
) {
1198 if (!(conflict
->flags
& IORESOURCE_BUSY
)) {
1203 if (conflict
->flags
& flags
& IORESOURCE_MUXED
) {
1204 add_wait_queue(&muxed_resource_wait
, &wait
);
1205 write_unlock(&resource_lock
);
1206 set_current_state(TASK_UNINTERRUPTIBLE
);
1208 remove_wait_queue(&muxed_resource_wait
, &wait
);
1209 write_lock(&resource_lock
);
1212 /* Uhhuh, that didn't work out.. */
1217 write_unlock(&resource_lock
);
1219 if (res
&& orig_parent
== &iomem_resource
)
1224 EXPORT_SYMBOL(__request_region
);
1227 * __release_region - release a previously reserved resource region
1228 * @parent: parent resource descriptor
1229 * @start: resource start address
1230 * @n: resource region size
1232 * The described resource region must match a currently busy region.
1234 void __release_region(struct resource
*parent
, resource_size_t start
,
1237 struct resource
**p
;
1238 resource_size_t end
;
1241 end
= start
+ n
- 1;
1243 write_lock(&resource_lock
);
1246 struct resource
*res
= *p
;
1250 if (res
->start
<= start
&& res
->end
>= end
) {
1251 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1255 if (res
->start
!= start
|| res
->end
!= end
)
1258 write_unlock(&resource_lock
);
1259 if (res
->flags
& IORESOURCE_MUXED
)
1260 wake_up(&muxed_resource_wait
);
1267 write_unlock(&resource_lock
);
1269 printk(KERN_WARNING
"Trying to free nonexistent resource "
1270 "<%016llx-%016llx>\n", (unsigned long long)start
,
1271 (unsigned long long)end
);
1273 EXPORT_SYMBOL(__release_region
);
1275 #ifdef CONFIG_MEMORY_HOTREMOVE
1277 * release_mem_region_adjustable - release a previously reserved memory region
1278 * @start: resource start address
1279 * @size: resource region size
1281 * This interface is intended for memory hot-delete. The requested region
1282 * is released from a currently busy memory resource. The requested region
1283 * must either match exactly or fit into a single busy resource entry. In
1284 * the latter case, the remaining resource is adjusted accordingly.
1285 * Existing children of the busy memory resource must be immutable in the
1289 * - Additional release conditions, such as overlapping region, can be
1290 * supported after they are confirmed as valid cases.
1291 * - When a busy memory resource gets split into two entries, the code
1292 * assumes that all children remain in the lower address entry for
1293 * simplicity. Enhance this logic when necessary.
1295 void release_mem_region_adjustable(resource_size_t start
, resource_size_t size
)
1297 struct resource
*parent
= &iomem_resource
;
1298 struct resource
*new_res
= NULL
;
1299 bool alloc_nofail
= false;
1300 struct resource
**p
;
1301 struct resource
*res
;
1302 resource_size_t end
;
1304 end
= start
+ size
- 1;
1305 if (WARN_ON_ONCE((start
< parent
->start
) || (end
> parent
->end
)))
1309 * We free up quite a lot of memory on memory hotunplug (esp., memap),
1310 * just before releasing the region. This is highly unlikely to
1311 * fail - let's play save and make it never fail as the caller cannot
1312 * perform any error handling (e.g., trying to re-add memory will fail
1316 new_res
= alloc_resource(GFP_KERNEL
| (alloc_nofail
? __GFP_NOFAIL
: 0));
1319 write_lock(&resource_lock
);
1321 while ((res
= *p
)) {
1322 if (res
->start
>= end
)
1325 /* look for the next resource if it does not fit into */
1326 if (res
->start
> start
|| res
->end
< end
) {
1332 * All memory regions added from memory-hotplug path have the
1333 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1334 * this flag, we know that we are dealing with a resource coming
1335 * from HMM/devm. HMM/devm use another mechanism to add/release
1336 * a resource. This goes via devm_request_mem_region and
1337 * devm_release_mem_region.
1338 * HMM/devm take care to release their resources when they want,
1339 * so if we are dealing with them, let us just back off here.
1341 if (!(res
->flags
& IORESOURCE_SYSRAM
)) {
1345 if (!(res
->flags
& IORESOURCE_MEM
))
1348 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1353 /* found the target resource; let's adjust accordingly */
1354 if (res
->start
== start
&& res
->end
== end
) {
1355 /* free the whole entry */
1358 } else if (res
->start
== start
&& res
->end
!= end
) {
1359 /* adjust the start */
1360 WARN_ON_ONCE(__adjust_resource(res
, end
+ 1,
1362 } else if (res
->start
!= start
&& res
->end
== end
) {
1363 /* adjust the end */
1364 WARN_ON_ONCE(__adjust_resource(res
, res
->start
,
1365 start
- res
->start
));
1367 /* split into two entries - we need a new resource */
1369 new_res
= alloc_resource(GFP_ATOMIC
);
1371 alloc_nofail
= true;
1372 write_unlock(&resource_lock
);
1376 new_res
->name
= res
->name
;
1377 new_res
->start
= end
+ 1;
1378 new_res
->end
= res
->end
;
1379 new_res
->flags
= res
->flags
;
1380 new_res
->desc
= res
->desc
;
1381 new_res
->parent
= res
->parent
;
1382 new_res
->sibling
= res
->sibling
;
1383 new_res
->child
= NULL
;
1385 if (WARN_ON_ONCE(__adjust_resource(res
, res
->start
,
1386 start
- res
->start
)))
1388 res
->sibling
= new_res
;
1395 write_unlock(&resource_lock
);
1396 free_resource(new_res
);
1398 #endif /* CONFIG_MEMORY_HOTREMOVE */
1400 #ifdef CONFIG_MEMORY_HOTPLUG
1401 static bool system_ram_resources_mergeable(struct resource
*r1
,
1402 struct resource
*r2
)
1404 /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1405 return r1
->flags
== r2
->flags
&& r1
->end
+ 1 == r2
->start
&&
1406 r1
->name
== r2
->name
&& r1
->desc
== r2
->desc
&&
1407 !r1
->child
&& !r2
->child
;
1411 * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1412 * merge it with adjacent, mergeable resources
1413 * @res: resource descriptor
1415 * This interface is intended for memory hotplug, whereby lots of contiguous
1416 * system ram resources are added (e.g., via add_memory*()) by a driver, and
1417 * the actual resource boundaries are not of interest (e.g., it might be
1418 * relevant for DIMMs). Only resources that are marked mergeable, that have the
1419 * same parent, and that don't have any children are considered. All mergeable
1420 * resources must be immutable during the request.
1423 * - The caller has to make sure that no pointers to resources that are
1424 * marked mergeable are used anymore after this call - the resource might
1425 * be freed and the pointer might be stale!
1426 * - release_mem_region_adjustable() will split on demand on memory hotunplug
1428 void merge_system_ram_resource(struct resource
*res
)
1430 const unsigned long flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
1431 struct resource
*cur
;
1433 if (WARN_ON_ONCE((res
->flags
& flags
) != flags
))
1436 write_lock(&resource_lock
);
1437 res
->flags
|= IORESOURCE_SYSRAM_MERGEABLE
;
1439 /* Try to merge with next item in the list. */
1441 if (cur
&& system_ram_resources_mergeable(res
, cur
)) {
1442 res
->end
= cur
->end
;
1443 res
->sibling
= cur
->sibling
;
1447 /* Try to merge with previous item in the list. */
1448 cur
= res
->parent
->child
;
1449 while (cur
&& cur
->sibling
!= res
)
1451 if (cur
&& system_ram_resources_mergeable(cur
, res
)) {
1452 cur
->end
= res
->end
;
1453 cur
->sibling
= res
->sibling
;
1456 write_unlock(&resource_lock
);
1458 #endif /* CONFIG_MEMORY_HOTPLUG */
1461 * Managed region resource
1463 static void devm_resource_release(struct device
*dev
, void *ptr
)
1465 struct resource
**r
= ptr
;
1467 release_resource(*r
);
1471 * devm_request_resource() - request and reserve an I/O or memory resource
1472 * @dev: device for which to request the resource
1473 * @root: root of the resource tree from which to request the resource
1474 * @new: descriptor of the resource to request
1476 * This is a device-managed version of request_resource(). There is usually
1477 * no need to release resources requested by this function explicitly since
1478 * that will be taken care of when the device is unbound from its driver.
1479 * If for some reason the resource needs to be released explicitly, because
1480 * of ordering issues for example, drivers must call devm_release_resource()
1481 * rather than the regular release_resource().
1483 * When a conflict is detected between any existing resources and the newly
1484 * requested resource, an error message will be printed.
1486 * Returns 0 on success or a negative error code on failure.
1488 int devm_request_resource(struct device
*dev
, struct resource
*root
,
1489 struct resource
*new)
1491 struct resource
*conflict
, **ptr
;
1493 ptr
= devres_alloc(devm_resource_release
, sizeof(*ptr
), GFP_KERNEL
);
1499 conflict
= request_resource_conflict(root
, new);
1501 dev_err(dev
, "resource collision: %pR conflicts with %s %pR\n",
1502 new, conflict
->name
, conflict
);
1507 devres_add(dev
, ptr
);
1510 EXPORT_SYMBOL(devm_request_resource
);
1512 static int devm_resource_match(struct device
*dev
, void *res
, void *data
)
1514 struct resource
**ptr
= res
;
1516 return *ptr
== data
;
1520 * devm_release_resource() - release a previously requested resource
1521 * @dev: device for which to release the resource
1522 * @new: descriptor of the resource to release
1524 * Releases a resource previously requested using devm_request_resource().
1526 void devm_release_resource(struct device
*dev
, struct resource
*new)
1528 WARN_ON(devres_release(dev
, devm_resource_release
, devm_resource_match
,
1531 EXPORT_SYMBOL(devm_release_resource
);
1533 struct region_devres
{
1534 struct resource
*parent
;
1535 resource_size_t start
;
1539 static void devm_region_release(struct device
*dev
, void *res
)
1541 struct region_devres
*this = res
;
1543 __release_region(this->parent
, this->start
, this->n
);
1546 static int devm_region_match(struct device
*dev
, void *res
, void *match_data
)
1548 struct region_devres
*this = res
, *match
= match_data
;
1550 return this->parent
== match
->parent
&&
1551 this->start
== match
->start
&& this->n
== match
->n
;
1555 __devm_request_region(struct device
*dev
, struct resource
*parent
,
1556 resource_size_t start
, resource_size_t n
, const char *name
)
1558 struct region_devres
*dr
= NULL
;
1559 struct resource
*res
;
1561 dr
= devres_alloc(devm_region_release
, sizeof(struct region_devres
),
1566 dr
->parent
= parent
;
1570 res
= __request_region(parent
, start
, n
, name
, 0);
1572 devres_add(dev
, dr
);
1578 EXPORT_SYMBOL(__devm_request_region
);
1580 void __devm_release_region(struct device
*dev
, struct resource
*parent
,
1581 resource_size_t start
, resource_size_t n
)
1583 struct region_devres match_data
= { parent
, start
, n
};
1585 __release_region(parent
, start
, n
);
1586 WARN_ON(devres_destroy(dev
, devm_region_release
, devm_region_match
,
1589 EXPORT_SYMBOL(__devm_release_region
);
1592 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1594 #define MAXRESERVE 4
1595 static int __init
reserve_setup(char *str
)
1597 static int reserved
;
1598 static struct resource reserve
[MAXRESERVE
];
1601 unsigned int io_start
, io_num
;
1603 struct resource
*parent
;
1605 if (get_option(&str
, &io_start
) != 2)
1607 if (get_option(&str
, &io_num
) == 0)
1609 if (x
< MAXRESERVE
) {
1610 struct resource
*res
= reserve
+ x
;
1613 * If the region starts below 0x10000, we assume it's
1614 * I/O port space; otherwise assume it's memory.
1616 if (io_start
< 0x10000) {
1617 res
->flags
= IORESOURCE_IO
;
1618 parent
= &ioport_resource
;
1620 res
->flags
= IORESOURCE_MEM
;
1621 parent
= &iomem_resource
;
1623 res
->name
= "reserved";
1624 res
->start
= io_start
;
1625 res
->end
= io_start
+ io_num
- 1;
1626 res
->flags
|= IORESOURCE_BUSY
;
1627 res
->desc
= IORES_DESC_NONE
;
1629 if (request_resource(parent
, res
) == 0)
1635 __setup("reserve=", reserve_setup
);
1638 * Check if the requested addr and size spans more than any slot in the
1639 * iomem resource tree.
1641 int iomem_map_sanity_check(resource_size_t addr
, unsigned long size
)
1643 struct resource
*p
= &iomem_resource
;
1647 read_lock(&resource_lock
);
1648 for (p
= p
->child
; p
; p
= r_next(NULL
, p
, &l
)) {
1650 * We can probably skip the resources without
1651 * IORESOURCE_IO attribute?
1653 if (p
->start
>= addr
+ size
)
1657 if (PFN_DOWN(p
->start
) <= PFN_DOWN(addr
) &&
1658 PFN_DOWN(p
->end
) >= PFN_DOWN(addr
+ size
- 1))
1661 * if a resource is "BUSY", it's not a hardware resource
1662 * but a driver mapping of such a resource; we don't want
1663 * to warn for those; some drivers legitimately map only
1664 * partial hardware resources. (example: vesafb)
1666 if (p
->flags
& IORESOURCE_BUSY
)
1669 printk(KERN_WARNING
"resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1670 (unsigned long long)addr
,
1671 (unsigned long long)(addr
+ size
- 1),
1676 read_unlock(&resource_lock
);
1681 #ifdef CONFIG_STRICT_DEVMEM
1682 static int strict_iomem_checks
= 1;
1684 static int strict_iomem_checks
;
1688 * check if an address is reserved in the iomem resource tree
1689 * returns true if reserved, false if not reserved.
1691 bool iomem_is_exclusive(u64 addr
)
1693 struct resource
*p
= &iomem_resource
;
1696 int size
= PAGE_SIZE
;
1698 if (!strict_iomem_checks
)
1701 addr
= addr
& PAGE_MASK
;
1703 read_lock(&resource_lock
);
1704 for (p
= p
->child
; p
; p
= r_next(NULL
, p
, &l
)) {
1706 * We can probably skip the resources without
1707 * IORESOURCE_IO attribute?
1709 if (p
->start
>= addr
+ size
)
1714 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1715 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1718 if ((p
->flags
& IORESOURCE_BUSY
) == 0)
1720 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM
)
1721 || p
->flags
& IORESOURCE_EXCLUSIVE
) {
1726 read_unlock(&resource_lock
);
1731 struct resource_entry
*resource_list_create_entry(struct resource
*res
,
1734 struct resource_entry
*entry
;
1736 entry
= kzalloc(sizeof(*entry
) + extra_size
, GFP_KERNEL
);
1738 INIT_LIST_HEAD(&entry
->node
);
1739 entry
->res
= res
? res
: &entry
->__res
;
1744 EXPORT_SYMBOL(resource_list_create_entry
);
1746 void resource_list_free(struct list_head
*head
)
1748 struct resource_entry
*entry
, *tmp
;
1750 list_for_each_entry_safe(entry
, tmp
, head
, node
)
1751 resource_list_destroy_entry(entry
);
1753 EXPORT_SYMBOL(resource_list_free
);
1755 #ifdef CONFIG_DEVICE_PRIVATE
1756 static struct resource
*__request_free_mem_region(struct device
*dev
,
1757 struct resource
*base
, unsigned long size
, const char *name
)
1759 resource_size_t end
, addr
;
1760 struct resource
*res
;
1762 size
= ALIGN(size
, 1UL << PA_SECTION_SHIFT
);
1763 end
= min_t(unsigned long, base
->end
, (1UL << MAX_PHYSMEM_BITS
) - 1);
1764 addr
= end
- size
+ 1UL;
1766 for (; addr
> size
&& addr
>= base
->start
; addr
-= size
) {
1767 if (region_intersects(addr
, size
, 0, IORES_DESC_NONE
) !=
1772 res
= devm_request_mem_region(dev
, addr
, size
, name
);
1774 res
= request_mem_region(addr
, size
, name
);
1776 return ERR_PTR(-ENOMEM
);
1777 res
->desc
= IORES_DESC_DEVICE_PRIVATE_MEMORY
;
1781 return ERR_PTR(-ERANGE
);
1785 * devm_request_free_mem_region - find free region for device private memory
1787 * @dev: device struct to bind the resource to
1788 * @size: size in bytes of the device memory to add
1789 * @base: resource tree to look in
1791 * This function tries to find an empty range of physical address big enough to
1792 * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1793 * memory, which in turn allocates struct pages.
1795 struct resource
*devm_request_free_mem_region(struct device
*dev
,
1796 struct resource
*base
, unsigned long size
)
1798 return __request_free_mem_region(dev
, base
, size
, dev_name(dev
));
1800 EXPORT_SYMBOL_GPL(devm_request_free_mem_region
);
1802 struct resource
*request_free_mem_region(struct resource
*base
,
1803 unsigned long size
, const char *name
)
1805 return __request_free_mem_region(NULL
, base
, size
, name
);
1807 EXPORT_SYMBOL_GPL(request_free_mem_region
);
1809 #endif /* CONFIG_DEVICE_PRIVATE */
1811 static int __init
strict_iomem(char *str
)
1813 if (strstr(str
, "relaxed"))
1814 strict_iomem_checks
= 0;
1815 if (strstr(str
, "strict"))
1816 strict_iomem_checks
= 1;
1820 static int iomem_fs_init_fs_context(struct fs_context
*fc
)
1822 return init_pseudo(fc
, DEVMEM_MAGIC
) ? 0 : -ENOMEM
;
1825 static struct file_system_type iomem_fs_type
= {
1827 .owner
= THIS_MODULE
,
1828 .init_fs_context
= iomem_fs_init_fs_context
,
1829 .kill_sb
= kill_anon_super
,
1832 static int __init
iomem_init_inode(void)
1834 static struct vfsmount
*iomem_vfs_mount
;
1835 static int iomem_fs_cnt
;
1836 struct inode
*inode
;
1839 rc
= simple_pin_fs(&iomem_fs_type
, &iomem_vfs_mount
, &iomem_fs_cnt
);
1841 pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc
);
1845 inode
= alloc_anon_inode(iomem_vfs_mount
->mnt_sb
);
1846 if (IS_ERR(inode
)) {
1847 rc
= PTR_ERR(inode
);
1848 pr_err("Cannot allocate inode for iomem: %d\n", rc
);
1849 simple_release_fs(&iomem_vfs_mount
, &iomem_fs_cnt
);
1854 * Publish iomem revocation inode initialized.
1855 * Pairs with smp_load_acquire() in revoke_iomem().
1857 smp_store_release(&iomem_inode
, inode
);
1862 fs_initcall(iomem_init_inode
);
1864 __setup("iomem=", strict_iomem
);