2 * linux/kernel/resource.c
4 * Copyright (C) 1999 Linus Torvalds
5 * Copyright (C) 1999 Martin Mares <mj@ucw.cz>
7 * Arbitrary resource management.
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/export.h>
13 #include <linux/errno.h>
14 #include <linux/ioport.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/spinlock.h>
19 #include <linux/proc_fs.h>
20 #include <linux/sched.h>
21 #include <linux/seq_file.h>
22 #include <linux/device.h>
23 #include <linux/pfn.h>
25 #include <linux/resource_ext.h>
29 struct resource ioport_resource
= {
32 .end
= IO_SPACE_LIMIT
,
33 .flags
= IORESOURCE_IO
,
35 EXPORT_SYMBOL(ioport_resource
);
37 struct resource iomem_resource
= {
41 .flags
= IORESOURCE_MEM
,
43 EXPORT_SYMBOL(iomem_resource
);
45 /* constraints to be met while allocating resources */
46 struct resource_constraint
{
47 resource_size_t min
, max
, align
;
48 resource_size_t (*alignf
)(void *, const struct resource
*,
49 resource_size_t
, resource_size_t
);
53 static DEFINE_RWLOCK(resource_lock
);
56 * For memory hotplug, there is no way to free resource entries allocated
57 * by boot mem after the system is up. So for reusing the resource entry
58 * we need to remember the resource.
60 static struct resource
*bootmem_resource_free
;
61 static DEFINE_SPINLOCK(bootmem_resource_lock
);
63 static struct resource
*next_resource(struct resource
*p
, bool sibling_only
)
65 /* Caller wants to traverse through siblings only */
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
, false);
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 * Finds the lowest iomem resource that covers part of [@start..@end]. The
323 * caller must specify @start, @end, @flags, and @desc (which may be
326 * If a resource is found, returns 0 and @*res is overwritten with the part
327 * of the resource that's within [@start..@end]; if none is found, returns
328 * -1 or -EINVAL for other invalid parameters.
330 * This function walks the whole tree and not just first level children
331 * unless @first_lvl is true.
333 * @start: start address of the resource searched for
334 * @end: end address of same resource
335 * @flags: flags which the resource must have
336 * @desc: descriptor the resource must have
337 * @first_lvl: walk only the first level children, if set
338 * @res: return ptr, if resource found
340 static int find_next_iomem_res(resource_size_t start
, resource_size_t end
,
341 unsigned long flags
, unsigned long desc
,
342 bool first_lvl
, struct resource
*res
)
352 read_lock(&resource_lock
);
354 for (p
= iomem_resource
.child
; p
; p
= next_resource(p
, first_lvl
)) {
355 if ((p
->flags
& flags
) != flags
)
357 if ((desc
!= IORES_DESC_NONE
) && (desc
!= p
->desc
))
359 if (p
->start
> end
) {
363 if ((p
->end
>= start
) && (p
->start
<= end
))
367 read_unlock(&resource_lock
);
372 res
->start
= max(start
, p
->start
);
373 res
->end
= min(end
, p
->end
);
374 res
->flags
= p
->flags
;
379 static int __walk_iomem_res_desc(resource_size_t start
, resource_size_t end
,
380 unsigned long flags
, unsigned long desc
,
381 bool first_lvl
, void *arg
,
382 int (*func
)(struct resource
*, void *))
387 while (start
< end
&&
388 !find_next_iomem_res(start
, end
, flags
, desc
, first_lvl
, &res
)) {
389 ret
= (*func
)(&res
, arg
);
400 * Walks through iomem resources and calls func() with matching resource
401 * ranges. This walks through whole tree and not just first level children.
402 * All the memory ranges which overlap start,end and also match flags and
403 * desc are valid candidates.
405 * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
406 * @flags: I/O resource flags
409 * @arg: function argument for the callback @func
410 * @func: callback function that is called for each qualifying resource area
412 * NOTE: For a new descriptor search, define a new IORES_DESC in
413 * <linux/ioport.h> and set it in 'desc' of a target resource entry.
415 int walk_iomem_res_desc(unsigned long desc
, unsigned long flags
, u64 start
,
416 u64 end
, void *arg
, int (*func
)(struct resource
*, void *))
418 return __walk_iomem_res_desc(start
, end
, flags
, desc
, false, arg
, func
);
420 EXPORT_SYMBOL_GPL(walk_iomem_res_desc
);
423 * This function calls the @func callback against all memory ranges of type
424 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
425 * Now, this function is only for System RAM, it deals with full ranges and
426 * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
429 int walk_system_ram_res(u64 start
, u64 end
, void *arg
,
430 int (*func
)(struct resource
*, void *))
432 unsigned long flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
434 return __walk_iomem_res_desc(start
, end
, flags
, IORES_DESC_NONE
, true,
439 * This function calls the @func callback against all memory ranges, which
440 * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
442 int walk_mem_res(u64 start
, u64 end
, void *arg
,
443 int (*func
)(struct resource
*, void *))
445 unsigned long flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
447 return __walk_iomem_res_desc(start
, end
, flags
, IORES_DESC_NONE
, true,
452 * This function calls the @func callback against all memory ranges of type
453 * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
454 * It is to be used only for System RAM.
456 * This will find System RAM ranges that are children of top-level resources
457 * in addition to top-level System RAM resources.
459 int walk_system_ram_range(unsigned long start_pfn
, unsigned long nr_pages
,
460 void *arg
, int (*func
)(unsigned long, unsigned long, void *))
462 resource_size_t start
, end
;
465 unsigned long pfn
, end_pfn
;
468 start
= (u64
) start_pfn
<< PAGE_SHIFT
;
469 end
= ((u64
)(start_pfn
+ nr_pages
) << PAGE_SHIFT
) - 1;
470 flags
= IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
;
471 while (start
< end
&&
472 !find_next_iomem_res(start
, end
, flags
, IORES_DESC_NONE
,
474 pfn
= (res
.start
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
475 end_pfn
= (res
.end
+ 1) >> PAGE_SHIFT
;
477 ret
= (*func
)(pfn
, end_pfn
- pfn
, arg
);
485 static int __is_ram(unsigned long pfn
, unsigned long nr_pages
, void *arg
)
491 * This generic page_is_ram() returns true if specified address is
492 * registered as System RAM in iomem_resource list.
494 int __weak
page_is_ram(unsigned long pfn
)
496 return walk_system_ram_range(pfn
, 1, NULL
, __is_ram
) == 1;
498 EXPORT_SYMBOL_GPL(page_is_ram
);
501 * region_intersects() - determine intersection of region with known resources
502 * @start: region start address
503 * @size: size of region
504 * @flags: flags of resource (in iomem_resource)
505 * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
507 * Check if the specified region partially overlaps or fully eclipses a
508 * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
509 * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
510 * return REGION_MIXED if the region overlaps @flags/@desc and another
511 * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
512 * and no other defined resource. Note that REGION_INTERSECTS is also
513 * returned in the case when the specified region overlaps RAM and undefined
516 * region_intersect() is used by memory remapping functions to ensure
517 * the user is not remapping RAM and is a vast speed up over walking
518 * through the resource table page by page.
520 int region_intersects(resource_size_t start
, size_t size
, unsigned long flags
,
524 int type
= 0; int other
= 0;
528 res
.end
= start
+ size
- 1;
530 read_lock(&resource_lock
);
531 for (p
= iomem_resource
.child
; p
; p
= p
->sibling
) {
532 bool is_type
= (((p
->flags
& flags
) == flags
) &&
533 ((desc
== IORES_DESC_NONE
) ||
536 if (resource_overlaps(p
, &res
))
537 is_type
? type
++ : other
++;
539 read_unlock(&resource_lock
);
542 return type
? REGION_INTERSECTS
: REGION_DISJOINT
;
547 return REGION_DISJOINT
;
549 EXPORT_SYMBOL_GPL(region_intersects
);
551 void __weak
arch_remove_reservations(struct resource
*avail
)
555 static resource_size_t
simple_align_resource(void *data
,
556 const struct resource
*avail
,
557 resource_size_t size
,
558 resource_size_t align
)
563 static void resource_clip(struct resource
*res
, resource_size_t min
,
566 if (res
->start
< min
)
573 * Find empty slot in the resource tree with the given range and
574 * alignment constraints
576 static int __find_resource(struct resource
*root
, struct resource
*old
,
577 struct resource
*new,
578 resource_size_t size
,
579 struct resource_constraint
*constraint
)
581 struct resource
*this = root
->child
;
582 struct resource tmp
= *new, avail
, alloc
;
584 tmp
.start
= root
->start
;
586 * Skip past an allocated resource that starts at 0, since the assignment
587 * of this->start - 1 to tmp->end below would cause an underflow.
589 if (this && this->start
== root
->start
) {
590 tmp
.start
= (this == old
) ? old
->start
: this->end
+ 1;
591 this = this->sibling
;
595 tmp
.end
= (this == old
) ? this->end
: this->start
- 1;
599 if (tmp
.end
< tmp
.start
)
602 resource_clip(&tmp
, constraint
->min
, constraint
->max
);
603 arch_remove_reservations(&tmp
);
605 /* Check for overflow after ALIGN() */
606 avail
.start
= ALIGN(tmp
.start
, constraint
->align
);
608 avail
.flags
= new->flags
& ~IORESOURCE_UNSET
;
609 if (avail
.start
>= tmp
.start
) {
610 alloc
.flags
= avail
.flags
;
611 alloc
.start
= constraint
->alignf(constraint
->alignf_data
, &avail
,
612 size
, constraint
->align
);
613 alloc
.end
= alloc
.start
+ size
- 1;
614 if (alloc
.start
<= alloc
.end
&&
615 resource_contains(&avail
, &alloc
)) {
616 new->start
= alloc
.start
;
617 new->end
= alloc
.end
;
622 next
: if (!this || this->end
== root
->end
)
626 tmp
.start
= this->end
+ 1;
627 this = this->sibling
;
633 * Find empty slot in the resource tree given range and alignment.
635 static int find_resource(struct resource
*root
, struct resource
*new,
636 resource_size_t size
,
637 struct resource_constraint
*constraint
)
639 return __find_resource(root
, NULL
, new, size
, constraint
);
643 * reallocate_resource - allocate a slot in the resource tree given range & alignment.
644 * The resource will be relocated if the new size cannot be reallocated in the
647 * @root: root resource descriptor
648 * @old: resource descriptor desired by caller
649 * @newsize: new size of the resource descriptor
650 * @constraint: the size and alignment constraints to be met.
652 static int reallocate_resource(struct resource
*root
, struct resource
*old
,
653 resource_size_t newsize
,
654 struct resource_constraint
*constraint
)
657 struct resource
new = *old
;
658 struct resource
*conflict
;
660 write_lock(&resource_lock
);
662 if ((err
= __find_resource(root
, old
, &new, newsize
, constraint
)))
665 if (resource_contains(&new, old
)) {
666 old
->start
= new.start
;
676 if (resource_contains(old
, &new)) {
677 old
->start
= new.start
;
680 __release_resource(old
, true);
682 conflict
= __request_resource(root
, old
);
686 write_unlock(&resource_lock
);
692 * allocate_resource - allocate empty slot in the resource tree given range & alignment.
693 * The resource will be reallocated with a new size if it was already allocated
694 * @root: root resource descriptor
695 * @new: resource descriptor desired by caller
696 * @size: requested resource region size
697 * @min: minimum boundary to allocate
698 * @max: maximum boundary to allocate
699 * @align: alignment requested, in bytes
700 * @alignf: alignment function, optional, called if not NULL
701 * @alignf_data: arbitrary data to pass to the @alignf function
703 int allocate_resource(struct resource
*root
, struct resource
*new,
704 resource_size_t size
, resource_size_t min
,
705 resource_size_t max
, resource_size_t align
,
706 resource_size_t (*alignf
)(void *,
707 const struct resource
*,
713 struct resource_constraint constraint
;
716 alignf
= simple_align_resource
;
718 constraint
.min
= min
;
719 constraint
.max
= max
;
720 constraint
.align
= align
;
721 constraint
.alignf
= alignf
;
722 constraint
.alignf_data
= alignf_data
;
725 /* resource is already allocated, try reallocating with
726 the new constraints */
727 return reallocate_resource(root
, new, size
, &constraint
);
730 write_lock(&resource_lock
);
731 err
= find_resource(root
, new, size
, &constraint
);
732 if (err
>= 0 && __request_resource(root
, new))
734 write_unlock(&resource_lock
);
738 EXPORT_SYMBOL(allocate_resource
);
741 * lookup_resource - find an existing resource by a resource start address
742 * @root: root resource descriptor
743 * @start: resource start address
745 * Returns a pointer to the resource if found, NULL otherwise
747 struct resource
*lookup_resource(struct resource
*root
, resource_size_t start
)
749 struct resource
*res
;
751 read_lock(&resource_lock
);
752 for (res
= root
->child
; res
; res
= res
->sibling
) {
753 if (res
->start
== start
)
756 read_unlock(&resource_lock
);
762 * Insert a resource into the resource tree. If successful, return NULL,
763 * otherwise return the conflicting resource (compare to __request_resource())
765 static struct resource
* __insert_resource(struct resource
*parent
, struct resource
*new)
767 struct resource
*first
, *next
;
769 for (;; parent
= first
) {
770 first
= __request_resource(parent
, new);
776 if (WARN_ON(first
== new)) /* duplicated insertion */
779 if ((first
->start
> new->start
) || (first
->end
< new->end
))
781 if ((first
->start
== new->start
) && (first
->end
== new->end
))
785 for (next
= first
; ; next
= next
->sibling
) {
786 /* Partial overlap? Bad, and unfixable */
787 if (next
->start
< new->start
|| next
->end
> new->end
)
791 if (next
->sibling
->start
> new->end
)
795 new->parent
= parent
;
796 new->sibling
= next
->sibling
;
799 next
->sibling
= NULL
;
800 for (next
= first
; next
; next
= next
->sibling
)
803 if (parent
->child
== first
) {
806 next
= parent
->child
;
807 while (next
->sibling
!= first
)
808 next
= next
->sibling
;
815 * insert_resource_conflict - Inserts resource in the resource tree
816 * @parent: parent of the new resource
817 * @new: new resource to insert
819 * Returns 0 on success, conflict resource if the resource can't be inserted.
821 * This function is equivalent to request_resource_conflict when no conflict
822 * happens. If a conflict happens, and the conflicting resources
823 * entirely fit within the range of the new resource, then the new
824 * resource is inserted and the conflicting resources become children of
827 * This function is intended for producers of resources, such as FW modules
830 struct resource
*insert_resource_conflict(struct resource
*parent
, struct resource
*new)
832 struct resource
*conflict
;
834 write_lock(&resource_lock
);
835 conflict
= __insert_resource(parent
, new);
836 write_unlock(&resource_lock
);
841 * insert_resource - Inserts a resource in the resource tree
842 * @parent: parent of the new resource
843 * @new: new resource to insert
845 * Returns 0 on success, -EBUSY if the resource can't be inserted.
847 * This function is intended for producers of resources, such as FW modules
850 int insert_resource(struct resource
*parent
, struct resource
*new)
852 struct resource
*conflict
;
854 conflict
= insert_resource_conflict(parent
, new);
855 return conflict
? -EBUSY
: 0;
857 EXPORT_SYMBOL_GPL(insert_resource
);
860 * insert_resource_expand_to_fit - Insert a resource into the resource tree
861 * @root: root resource descriptor
862 * @new: new resource to insert
864 * Insert a resource into the resource tree, possibly expanding it in order
865 * to make it encompass any conflicting resources.
867 void insert_resource_expand_to_fit(struct resource
*root
, struct resource
*new)
872 write_lock(&resource_lock
);
874 struct resource
*conflict
;
876 conflict
= __insert_resource(root
, new);
879 if (conflict
== root
)
882 /* Ok, expand resource to cover the conflict, then try again .. */
883 if (conflict
->start
< new->start
)
884 new->start
= conflict
->start
;
885 if (conflict
->end
> new->end
)
886 new->end
= conflict
->end
;
888 printk("Expanded resource %s due to conflict with %s\n", new->name
, conflict
->name
);
890 write_unlock(&resource_lock
);
894 * remove_resource - Remove a resource in the resource tree
895 * @old: resource to remove
897 * Returns 0 on success, -EINVAL if the resource is not valid.
899 * This function removes a resource previously inserted by insert_resource()
900 * or insert_resource_conflict(), and moves the children (if any) up to
901 * where they were before. insert_resource() and insert_resource_conflict()
902 * insert a new resource, and move any conflicting resources down to the
903 * children of the new resource.
905 * insert_resource(), insert_resource_conflict() and remove_resource() are
906 * intended for producers of resources, such as FW modules and bus drivers.
908 int remove_resource(struct resource
*old
)
912 write_lock(&resource_lock
);
913 retval
= __release_resource(old
, false);
914 write_unlock(&resource_lock
);
917 EXPORT_SYMBOL_GPL(remove_resource
);
919 static int __adjust_resource(struct resource
*res
, resource_size_t start
,
920 resource_size_t size
)
922 struct resource
*tmp
, *parent
= res
->parent
;
923 resource_size_t end
= start
+ size
- 1;
929 if ((start
< parent
->start
) || (end
> parent
->end
))
932 if (res
->sibling
&& (res
->sibling
->start
<= end
))
937 while (tmp
->sibling
!= res
)
939 if (start
<= tmp
->end
)
944 for (tmp
= res
->child
; tmp
; tmp
= tmp
->sibling
)
945 if ((tmp
->start
< start
) || (tmp
->end
> end
))
957 * adjust_resource - modify a resource's start and size
958 * @res: resource to modify
959 * @start: new start value
962 * Given an existing resource, change its start and size to match the
963 * arguments. Returns 0 on success, -EBUSY if it can't fit.
964 * Existing children of the resource are assumed to be immutable.
966 int adjust_resource(struct resource
*res
, resource_size_t start
,
967 resource_size_t size
)
971 write_lock(&resource_lock
);
972 result
= __adjust_resource(res
, start
, size
);
973 write_unlock(&resource_lock
);
976 EXPORT_SYMBOL(adjust_resource
);
979 __reserve_region_with_split(struct resource
*root
, resource_size_t start
,
980 resource_size_t end
, const char *name
)
982 struct resource
*parent
= root
;
983 struct resource
*conflict
;
984 struct resource
*res
= alloc_resource(GFP_ATOMIC
);
985 struct resource
*next_res
= NULL
;
986 int type
= resource_type(root
);
994 res
->flags
= type
| IORESOURCE_BUSY
;
995 res
->desc
= IORES_DESC_NONE
;
999 conflict
= __request_resource(parent
, res
);
1008 /* conflict covered whole area */
1009 if (conflict
->start
<= res
->start
&&
1010 conflict
->end
>= res
->end
) {
1016 /* failed, split and try again */
1017 if (conflict
->start
> res
->start
) {
1019 res
->end
= conflict
->start
- 1;
1020 if (conflict
->end
< end
) {
1021 next_res
= alloc_resource(GFP_ATOMIC
);
1026 next_res
->name
= name
;
1027 next_res
->start
= conflict
->end
+ 1;
1028 next_res
->end
= end
;
1029 next_res
->flags
= type
| IORESOURCE_BUSY
;
1030 next_res
->desc
= IORES_DESC_NONE
;
1033 res
->start
= conflict
->end
+ 1;
1040 reserve_region_with_split(struct resource
*root
, resource_size_t start
,
1041 resource_size_t end
, const char *name
)
1045 write_lock(&resource_lock
);
1046 if (root
->start
> start
|| root
->end
< end
) {
1047 pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1048 (unsigned long long)start
, (unsigned long long)end
,
1050 if (start
> root
->end
|| end
< root
->start
)
1053 if (end
> root
->end
)
1055 if (start
< root
->start
)
1056 start
= root
->start
;
1057 pr_err("fixing request to [0x%llx-0x%llx]\n",
1058 (unsigned long long)start
,
1059 (unsigned long long)end
);
1064 __reserve_region_with_split(root
, start
, end
, name
);
1065 write_unlock(&resource_lock
);
1069 * resource_alignment - calculate resource's alignment
1070 * @res: resource pointer
1072 * Returns alignment on success, 0 (invalid alignment) on failure.
1074 resource_size_t
resource_alignment(struct resource
*res
)
1076 switch (res
->flags
& (IORESOURCE_SIZEALIGN
| IORESOURCE_STARTALIGN
)) {
1077 case IORESOURCE_SIZEALIGN
:
1078 return resource_size(res
);
1079 case IORESOURCE_STARTALIGN
:
1087 * This is compatibility stuff for IO resources.
1089 * Note how this, unlike the above, knows about
1090 * the IO flag meanings (busy etc).
1092 * request_region creates a new busy region.
1094 * release_region releases a matching busy region.
1097 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait
);
1100 * __request_region - create a new busy resource region
1101 * @parent: parent resource descriptor
1102 * @start: resource start address
1103 * @n: resource region size
1104 * @name: reserving caller's ID string
1105 * @flags: IO resource flags
1107 struct resource
* __request_region(struct resource
*parent
,
1108 resource_size_t start
, resource_size_t n
,
1109 const char *name
, int flags
)
1111 DECLARE_WAITQUEUE(wait
, current
);
1112 struct resource
*res
= alloc_resource(GFP_KERNEL
);
1119 res
->end
= start
+ n
- 1;
1121 write_lock(&resource_lock
);
1124 struct resource
*conflict
;
1126 res
->flags
= resource_type(parent
) | resource_ext_type(parent
);
1127 res
->flags
|= IORESOURCE_BUSY
| flags
;
1128 res
->desc
= parent
->desc
;
1130 conflict
= __request_resource(parent
, res
);
1134 * mm/hmm.c reserves physical addresses which then
1135 * become unavailable to other users. Conflicts are
1136 * not expected. Warn to aid debugging if encountered.
1138 if (conflict
->desc
== IORES_DESC_DEVICE_PRIVATE_MEMORY
) {
1139 pr_warn("Unaddressable device %s %pR conflicts with %pR",
1140 conflict
->name
, conflict
, res
);
1142 if (conflict
!= parent
) {
1143 if (!(conflict
->flags
& IORESOURCE_BUSY
)) {
1148 if (conflict
->flags
& flags
& IORESOURCE_MUXED
) {
1149 add_wait_queue(&muxed_resource_wait
, &wait
);
1150 write_unlock(&resource_lock
);
1151 set_current_state(TASK_UNINTERRUPTIBLE
);
1153 remove_wait_queue(&muxed_resource_wait
, &wait
);
1154 write_lock(&resource_lock
);
1157 /* Uhhuh, that didn't work out.. */
1162 write_unlock(&resource_lock
);
1165 EXPORT_SYMBOL(__request_region
);
1168 * __release_region - release a previously reserved resource region
1169 * @parent: parent resource descriptor
1170 * @start: resource start address
1171 * @n: resource region size
1173 * The described resource region must match a currently busy region.
1175 void __release_region(struct resource
*parent
, resource_size_t start
,
1178 struct resource
**p
;
1179 resource_size_t end
;
1182 end
= start
+ n
- 1;
1184 write_lock(&resource_lock
);
1187 struct resource
*res
= *p
;
1191 if (res
->start
<= start
&& res
->end
>= end
) {
1192 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1196 if (res
->start
!= start
|| res
->end
!= end
)
1199 write_unlock(&resource_lock
);
1200 if (res
->flags
& IORESOURCE_MUXED
)
1201 wake_up(&muxed_resource_wait
);
1208 write_unlock(&resource_lock
);
1210 printk(KERN_WARNING
"Trying to free nonexistent resource "
1211 "<%016llx-%016llx>\n", (unsigned long long)start
,
1212 (unsigned long long)end
);
1214 EXPORT_SYMBOL(__release_region
);
1216 #ifdef CONFIG_MEMORY_HOTREMOVE
1218 * release_mem_region_adjustable - release a previously reserved memory region
1219 * @parent: parent resource descriptor
1220 * @start: resource start address
1221 * @size: resource region size
1223 * This interface is intended for memory hot-delete. The requested region
1224 * is released from a currently busy memory resource. The requested region
1225 * must either match exactly or fit into a single busy resource entry. In
1226 * the latter case, the remaining resource is adjusted accordingly.
1227 * Existing children of the busy memory resource must be immutable in the
1231 * - Additional release conditions, such as overlapping region, can be
1232 * supported after they are confirmed as valid cases.
1233 * - When a busy memory resource gets split into two entries, the code
1234 * assumes that all children remain in the lower address entry for
1235 * simplicity. Enhance this logic when necessary.
1237 int release_mem_region_adjustable(struct resource
*parent
,
1238 resource_size_t start
, resource_size_t size
)
1240 struct resource
**p
;
1241 struct resource
*res
;
1242 struct resource
*new_res
;
1243 resource_size_t end
;
1246 end
= start
+ size
- 1;
1247 if ((start
< parent
->start
) || (end
> parent
->end
))
1250 /* The alloc_resource() result gets checked later */
1251 new_res
= alloc_resource(GFP_KERNEL
);
1254 write_lock(&resource_lock
);
1256 while ((res
= *p
)) {
1257 if (res
->start
>= end
)
1260 /* look for the next resource if it does not fit into */
1261 if (res
->start
> start
|| res
->end
< end
) {
1267 * All memory regions added from memory-hotplug path have the
1268 * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1269 * this flag, we know that we are dealing with a resource coming
1270 * from HMM/devm. HMM/devm use another mechanism to add/release
1271 * a resource. This goes via devm_request_mem_region and
1272 * devm_release_mem_region.
1273 * HMM/devm take care to release their resources when they want,
1274 * so if we are dealing with them, let us just back off here.
1276 if (!(res
->flags
& IORESOURCE_SYSRAM
)) {
1281 if (!(res
->flags
& IORESOURCE_MEM
))
1284 if (!(res
->flags
& IORESOURCE_BUSY
)) {
1289 /* found the target resource; let's adjust accordingly */
1290 if (res
->start
== start
&& res
->end
== end
) {
1291 /* free the whole entry */
1295 } else if (res
->start
== start
&& res
->end
!= end
) {
1296 /* adjust the start */
1297 ret
= __adjust_resource(res
, end
+ 1,
1299 } else if (res
->start
!= start
&& res
->end
== end
) {
1300 /* adjust the end */
1301 ret
= __adjust_resource(res
, res
->start
,
1302 start
- res
->start
);
1304 /* split into two entries */
1309 new_res
->name
= res
->name
;
1310 new_res
->start
= end
+ 1;
1311 new_res
->end
= res
->end
;
1312 new_res
->flags
= res
->flags
;
1313 new_res
->desc
= res
->desc
;
1314 new_res
->parent
= res
->parent
;
1315 new_res
->sibling
= res
->sibling
;
1316 new_res
->child
= NULL
;
1318 ret
= __adjust_resource(res
, res
->start
,
1319 start
- res
->start
);
1322 res
->sibling
= new_res
;
1329 write_unlock(&resource_lock
);
1330 free_resource(new_res
);
1333 #endif /* CONFIG_MEMORY_HOTREMOVE */
1336 * Managed region resource
1338 static void devm_resource_release(struct device
*dev
, void *ptr
)
1340 struct resource
**r
= ptr
;
1342 release_resource(*r
);
1346 * devm_request_resource() - request and reserve an I/O or memory resource
1347 * @dev: device for which to request the resource
1348 * @root: root of the resource tree from which to request the resource
1349 * @new: descriptor of the resource to request
1351 * This is a device-managed version of request_resource(). There is usually
1352 * no need to release resources requested by this function explicitly since
1353 * that will be taken care of when the device is unbound from its driver.
1354 * If for some reason the resource needs to be released explicitly, because
1355 * of ordering issues for example, drivers must call devm_release_resource()
1356 * rather than the regular release_resource().
1358 * When a conflict is detected between any existing resources and the newly
1359 * requested resource, an error message will be printed.
1361 * Returns 0 on success or a negative error code on failure.
1363 int devm_request_resource(struct device
*dev
, struct resource
*root
,
1364 struct resource
*new)
1366 struct resource
*conflict
, **ptr
;
1368 ptr
= devres_alloc(devm_resource_release
, sizeof(*ptr
), GFP_KERNEL
);
1374 conflict
= request_resource_conflict(root
, new);
1376 dev_err(dev
, "resource collision: %pR conflicts with %s %pR\n",
1377 new, conflict
->name
, conflict
);
1382 devres_add(dev
, ptr
);
1385 EXPORT_SYMBOL(devm_request_resource
);
1387 static int devm_resource_match(struct device
*dev
, void *res
, void *data
)
1389 struct resource
**ptr
= res
;
1391 return *ptr
== data
;
1395 * devm_release_resource() - release a previously requested resource
1396 * @dev: device for which to release the resource
1397 * @new: descriptor of the resource to release
1399 * Releases a resource previously requested using devm_request_resource().
1401 void devm_release_resource(struct device
*dev
, struct resource
*new)
1403 WARN_ON(devres_release(dev
, devm_resource_release
, devm_resource_match
,
1406 EXPORT_SYMBOL(devm_release_resource
);
1408 struct region_devres
{
1409 struct resource
*parent
;
1410 resource_size_t start
;
1414 static void devm_region_release(struct device
*dev
, void *res
)
1416 struct region_devres
*this = res
;
1418 __release_region(this->parent
, this->start
, this->n
);
1421 static int devm_region_match(struct device
*dev
, void *res
, void *match_data
)
1423 struct region_devres
*this = res
, *match
= match_data
;
1425 return this->parent
== match
->parent
&&
1426 this->start
== match
->start
&& this->n
== match
->n
;
1430 __devm_request_region(struct device
*dev
, struct resource
*parent
,
1431 resource_size_t start
, resource_size_t n
, const char *name
)
1433 struct region_devres
*dr
= NULL
;
1434 struct resource
*res
;
1436 dr
= devres_alloc(devm_region_release
, sizeof(struct region_devres
),
1441 dr
->parent
= parent
;
1445 res
= __request_region(parent
, start
, n
, name
, 0);
1447 devres_add(dev
, dr
);
1453 EXPORT_SYMBOL(__devm_request_region
);
1455 void __devm_release_region(struct device
*dev
, struct resource
*parent
,
1456 resource_size_t start
, resource_size_t n
)
1458 struct region_devres match_data
= { parent
, start
, n
};
1460 __release_region(parent
, start
, n
);
1461 WARN_ON(devres_destroy(dev
, devm_region_release
, devm_region_match
,
1464 EXPORT_SYMBOL(__devm_release_region
);
1467 * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1469 #define MAXRESERVE 4
1470 static int __init
reserve_setup(char *str
)
1472 static int reserved
;
1473 static struct resource reserve
[MAXRESERVE
];
1476 unsigned int io_start
, io_num
;
1478 struct resource
*parent
;
1480 if (get_option(&str
, &io_start
) != 2)
1482 if (get_option(&str
, &io_num
) == 0)
1484 if (x
< MAXRESERVE
) {
1485 struct resource
*res
= reserve
+ x
;
1488 * If the region starts below 0x10000, we assume it's
1489 * I/O port space; otherwise assume it's memory.
1491 if (io_start
< 0x10000) {
1492 res
->flags
= IORESOURCE_IO
;
1493 parent
= &ioport_resource
;
1495 res
->flags
= IORESOURCE_MEM
;
1496 parent
= &iomem_resource
;
1498 res
->name
= "reserved";
1499 res
->start
= io_start
;
1500 res
->end
= io_start
+ io_num
- 1;
1501 res
->flags
|= IORESOURCE_BUSY
;
1502 res
->desc
= IORES_DESC_NONE
;
1504 if (request_resource(parent
, res
) == 0)
1510 __setup("reserve=", reserve_setup
);
1513 * Check if the requested addr and size spans more than any slot in the
1514 * iomem resource tree.
1516 int iomem_map_sanity_check(resource_size_t addr
, unsigned long size
)
1518 struct resource
*p
= &iomem_resource
;
1522 read_lock(&resource_lock
);
1523 for (p
= p
->child
; p
; p
= r_next(NULL
, p
, &l
)) {
1525 * We can probably skip the resources without
1526 * IORESOURCE_IO attribute?
1528 if (p
->start
>= addr
+ size
)
1532 if (PFN_DOWN(p
->start
) <= PFN_DOWN(addr
) &&
1533 PFN_DOWN(p
->end
) >= PFN_DOWN(addr
+ size
- 1))
1536 * if a resource is "BUSY", it's not a hardware resource
1537 * but a driver mapping of such a resource; we don't want
1538 * to warn for those; some drivers legitimately map only
1539 * partial hardware resources. (example: vesafb)
1541 if (p
->flags
& IORESOURCE_BUSY
)
1544 printk(KERN_WARNING
"resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1545 (unsigned long long)addr
,
1546 (unsigned long long)(addr
+ size
- 1),
1551 read_unlock(&resource_lock
);
1556 #ifdef CONFIG_STRICT_DEVMEM
1557 static int strict_iomem_checks
= 1;
1559 static int strict_iomem_checks
;
1563 * check if an address is reserved in the iomem resource tree
1564 * returns true if reserved, false if not reserved.
1566 bool iomem_is_exclusive(u64 addr
)
1568 struct resource
*p
= &iomem_resource
;
1571 int size
= PAGE_SIZE
;
1573 if (!strict_iomem_checks
)
1576 addr
= addr
& PAGE_MASK
;
1578 read_lock(&resource_lock
);
1579 for (p
= p
->child
; p
; p
= r_next(NULL
, p
, &l
)) {
1581 * We can probably skip the resources without
1582 * IORESOURCE_IO attribute?
1584 if (p
->start
>= addr
+ size
)
1589 * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1590 * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1593 if ((p
->flags
& IORESOURCE_BUSY
) == 0)
1595 if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM
)
1596 || p
->flags
& IORESOURCE_EXCLUSIVE
) {
1601 read_unlock(&resource_lock
);
1606 struct resource_entry
*resource_list_create_entry(struct resource
*res
,
1609 struct resource_entry
*entry
;
1611 entry
= kzalloc(sizeof(*entry
) + extra_size
, GFP_KERNEL
);
1613 INIT_LIST_HEAD(&entry
->node
);
1614 entry
->res
= res
? res
: &entry
->__res
;
1619 EXPORT_SYMBOL(resource_list_create_entry
);
1621 void resource_list_free(struct list_head
*head
)
1623 struct resource_entry
*entry
, *tmp
;
1625 list_for_each_entry_safe(entry
, tmp
, head
, node
)
1626 resource_list_destroy_entry(entry
);
1628 EXPORT_SYMBOL(resource_list_free
);
1630 static int __init
strict_iomem(char *str
)
1632 if (strstr(str
, "relaxed"))
1633 strict_iomem_checks
= 0;
1634 if (strstr(str
, "strict"))
1635 strict_iomem_checks
= 1;
1639 __setup("iomem=", strict_iomem
);