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 #include <linux/module.h>
11 #include <linux/errno.h>
12 #include <linux/ioport.h>
13 #include <linux/init.h>
14 #include <linux/slab.h>
15 #include <linux/spinlock.h>
17 #include <linux/proc_fs.h>
18 #include <linux/sched.h>
19 #include <linux/seq_file.h>
20 #include <linux/device.h>
21 #include <linux/pfn.h>
25 struct resource ioport_resource
= {
28 .end
= IO_SPACE_LIMIT
,
29 .flags
= IORESOURCE_IO
,
31 EXPORT_SYMBOL(ioport_resource
);
33 struct resource iomem_resource
= {
37 .flags
= IORESOURCE_MEM
,
39 EXPORT_SYMBOL(iomem_resource
);
41 static DEFINE_RWLOCK(resource_lock
);
43 static void *r_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
45 struct resource
*p
= v
;
49 while (!p
->sibling
&& p
->parent
)
56 enum { MAX_IORES_LEVEL
= 5 };
58 static void *r_start(struct seq_file
*m
, loff_t
*pos
)
59 __acquires(resource_lock
)
61 struct resource
*p
= m
->private;
63 read_lock(&resource_lock
);
64 for (p
= p
->child
; p
&& l
< *pos
; p
= r_next(m
, p
, &l
))
69 static void r_stop(struct seq_file
*m
, void *v
)
70 __releases(resource_lock
)
72 read_unlock(&resource_lock
);
75 static int r_show(struct seq_file
*m
, void *v
)
77 struct resource
*root
= m
->private;
78 struct resource
*r
= v
, *p
;
79 int width
= root
->end
< 0x10000 ? 4 : 8;
82 for (depth
= 0, p
= r
; depth
< MAX_IORES_LEVEL
; depth
++, p
= p
->parent
)
83 if (p
->parent
== root
)
85 seq_printf(m
, "%*s%0*llx-%0*llx : %s\n",
87 width
, (unsigned long long) r
->start
,
88 width
, (unsigned long long) r
->end
,
89 r
->name
? r
->name
: "<BAD>");
93 static const struct seq_operations resource_op
= {
100 static int ioports_open(struct inode
*inode
, struct file
*file
)
102 int res
= seq_open(file
, &resource_op
);
104 struct seq_file
*m
= file
->private_data
;
105 m
->private = &ioport_resource
;
110 static int iomem_open(struct inode
*inode
, struct file
*file
)
112 int res
= seq_open(file
, &resource_op
);
114 struct seq_file
*m
= file
->private_data
;
115 m
->private = &iomem_resource
;
120 static const struct file_operations proc_ioports_operations
= {
121 .open
= ioports_open
,
124 .release
= seq_release
,
127 static const struct file_operations proc_iomem_operations
= {
131 .release
= seq_release
,
134 static int __init
ioresources_init(void)
136 proc_create("ioports", 0, NULL
, &proc_ioports_operations
);
137 proc_create("iomem", 0, NULL
, &proc_iomem_operations
);
140 __initcall(ioresources_init
);
142 #endif /* CONFIG_PROC_FS */
144 /* Return the conflict entry if you can't request it */
145 static struct resource
* __request_resource(struct resource
*root
, struct resource
*new)
147 resource_size_t start
= new->start
;
148 resource_size_t end
= new->end
;
149 struct resource
*tmp
, **p
;
153 if (start
< root
->start
)
160 if (!tmp
|| tmp
->start
> end
) {
167 if (tmp
->end
< start
)
173 static int __release_resource(struct resource
*old
)
175 struct resource
*tmp
, **p
;
177 p
= &old
->parent
->child
;
192 static void __release_child_resources(struct resource
*r
)
194 struct resource
*tmp
, *p
;
195 resource_size_t size
;
205 __release_child_resources(tmp
);
207 printk(KERN_DEBUG
"release child resource %pR\n", tmp
);
208 /* need to restore size, and keep flags */
209 size
= resource_size(tmp
);
215 void release_child_resources(struct resource
*r
)
217 write_lock(&resource_lock
);
218 __release_child_resources(r
);
219 write_unlock(&resource_lock
);
223 * request_resource_conflict - request and reserve an I/O or memory resource
224 * @root: root resource descriptor
225 * @new: resource descriptor desired by caller
227 * Returns 0 for success, conflict resource on error.
229 struct resource
*request_resource_conflict(struct resource
*root
, struct resource
*new)
231 struct resource
*conflict
;
233 write_lock(&resource_lock
);
234 conflict
= __request_resource(root
, new);
235 write_unlock(&resource_lock
);
240 * request_resource - request and reserve an I/O or memory resource
241 * @root: root resource descriptor
242 * @new: resource descriptor desired by caller
244 * Returns 0 for success, negative error code on error.
246 int request_resource(struct resource
*root
, struct resource
*new)
248 struct resource
*conflict
;
250 conflict
= request_resource_conflict(root
, new);
251 return conflict
? -EBUSY
: 0;
254 EXPORT_SYMBOL(request_resource
);
257 * release_resource - release a previously reserved resource
258 * @old: resource pointer
260 int release_resource(struct resource
*old
)
264 write_lock(&resource_lock
);
265 retval
= __release_resource(old
);
266 write_unlock(&resource_lock
);
270 EXPORT_SYMBOL(release_resource
);
272 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
274 * Finds the lowest memory reosurce exists within [res->start.res->end)
275 * the caller must specify res->start, res->end, res->flags and "name".
276 * If found, returns 0, res is overwritten, if not found, returns -1.
278 static int find_next_system_ram(struct resource
*res
, char *name
)
280 resource_size_t start
, end
;
287 BUG_ON(start
>= end
);
289 read_lock(&resource_lock
);
290 for (p
= iomem_resource
.child
; p
; p
= p
->sibling
) {
291 /* system ram is just marked as IORESOURCE_MEM */
292 if (p
->flags
!= res
->flags
)
294 if (name
&& strcmp(p
->name
, name
))
296 if (p
->start
> end
) {
300 if ((p
->end
>= start
) && (p
->start
< end
))
303 read_unlock(&resource_lock
);
307 if (res
->start
< p
->start
)
308 res
->start
= p
->start
;
309 if (res
->end
> p
->end
)
315 * This function calls callback against all memory range of "System RAM"
316 * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY.
317 * Now, this function is only for "System RAM".
319 int walk_system_ram_range(unsigned long start_pfn
, unsigned long nr_pages
,
320 void *arg
, int (*func
)(unsigned long, unsigned long, void *))
323 unsigned long pfn
, end_pfn
;
327 res
.start
= (u64
) start_pfn
<< PAGE_SHIFT
;
328 res
.end
= ((u64
)(start_pfn
+ nr_pages
) << PAGE_SHIFT
) - 1;
329 res
.flags
= IORESOURCE_MEM
| IORESOURCE_BUSY
;
331 while ((res
.start
< res
.end
) &&
332 (find_next_system_ram(&res
, "System RAM") >= 0)) {
333 pfn
= (res
.start
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
334 end_pfn
= (res
.end
+ 1) >> PAGE_SHIFT
;
336 ret
= (*func
)(pfn
, end_pfn
- pfn
, arg
);
339 res
.start
= res
.end
+ 1;
347 static int __is_ram(unsigned long pfn
, unsigned long nr_pages
, void *arg
)
352 * This generic page_is_ram() returns true if specified address is
353 * registered as "System RAM" in iomem_resource list.
355 int __weak
page_is_ram(unsigned long pfn
)
357 return walk_system_ram_range(pfn
, 1, NULL
, __is_ram
) == 1;
360 static resource_size_t
simple_align_resource(void *data
,
361 const struct resource
*avail
,
362 resource_size_t size
,
363 resource_size_t align
)
368 static void resource_clip(struct resource
*res
, resource_size_t min
,
371 if (res
->start
< min
)
377 static bool resource_contains(struct resource
*res1
, struct resource
*res2
)
379 return res1
->start
<= res2
->start
&& res1
->end
>= res2
->end
;
383 * Find empty slot in the resource tree given range and alignment.
385 static int find_resource(struct resource
*root
, struct resource
*new,
386 resource_size_t size
, resource_size_t min
,
387 resource_size_t max
, resource_size_t align
,
388 resource_size_t (*alignf
)(void *,
389 const struct resource
*,
394 struct resource
*this = root
->child
;
395 struct resource tmp
= *new, avail
, alloc
;
397 tmp
.start
= root
->start
;
399 * Skip past an allocated resource that starts at 0, since the assignment
400 * of this->start - 1 to tmp->end below would cause an underflow.
402 if (this && this->start
== 0) {
403 tmp
.start
= this->end
+ 1;
404 this = this->sibling
;
408 tmp
.end
= this->start
- 1;
412 resource_clip(&tmp
, min
, max
);
414 /* Check for overflow after ALIGN() */
416 avail
.start
= ALIGN(tmp
.start
, align
);
418 if (avail
.start
>= tmp
.start
) {
419 alloc
.start
= alignf(alignf_data
, &avail
, size
, align
);
420 alloc
.end
= alloc
.start
+ size
- 1;
421 if (resource_contains(&avail
, &alloc
)) {
422 new->start
= alloc
.start
;
423 new->end
= alloc
.end
;
429 tmp
.start
= this->end
+ 1;
430 this = this->sibling
;
436 * allocate_resource - allocate empty slot in the resource tree given range & alignment
437 * @root: root resource descriptor
438 * @new: resource descriptor desired by caller
439 * @size: requested resource region size
440 * @min: minimum size to allocate
441 * @max: maximum size to allocate
442 * @align: alignment requested, in bytes
443 * @alignf: alignment function, optional, called if not NULL
444 * @alignf_data: arbitrary data to pass to the @alignf function
446 int allocate_resource(struct resource
*root
, struct resource
*new,
447 resource_size_t size
, resource_size_t min
,
448 resource_size_t max
, resource_size_t align
,
449 resource_size_t (*alignf
)(void *,
450 const struct resource
*,
458 alignf
= simple_align_resource
;
460 write_lock(&resource_lock
);
461 err
= find_resource(root
, new, size
, min
, max
, align
, alignf
, alignf_data
);
462 if (err
>= 0 && __request_resource(root
, new))
464 write_unlock(&resource_lock
);
468 EXPORT_SYMBOL(allocate_resource
);
471 * Insert a resource into the resource tree. If successful, return NULL,
472 * otherwise return the conflicting resource (compare to __request_resource())
474 static struct resource
* __insert_resource(struct resource
*parent
, struct resource
*new)
476 struct resource
*first
, *next
;
478 for (;; parent
= first
) {
479 first
= __request_resource(parent
, new);
485 if (WARN_ON(first
== new)) /* duplicated insertion */
488 if ((first
->start
> new->start
) || (first
->end
< new->end
))
490 if ((first
->start
== new->start
) && (first
->end
== new->end
))
494 for (next
= first
; ; next
= next
->sibling
) {
495 /* Partial overlap? Bad, and unfixable */
496 if (next
->start
< new->start
|| next
->end
> new->end
)
500 if (next
->sibling
->start
> new->end
)
504 new->parent
= parent
;
505 new->sibling
= next
->sibling
;
508 next
->sibling
= NULL
;
509 for (next
= first
; next
; next
= next
->sibling
)
512 if (parent
->child
== first
) {
515 next
= parent
->child
;
516 while (next
->sibling
!= first
)
517 next
= next
->sibling
;
524 * insert_resource_conflict - Inserts resource in the resource tree
525 * @parent: parent of the new resource
526 * @new: new resource to insert
528 * Returns 0 on success, conflict resource if the resource can't be inserted.
530 * This function is equivalent to request_resource_conflict when no conflict
531 * happens. If a conflict happens, and the conflicting resources
532 * entirely fit within the range of the new resource, then the new
533 * resource is inserted and the conflicting resources become children of
536 struct resource
*insert_resource_conflict(struct resource
*parent
, struct resource
*new)
538 struct resource
*conflict
;
540 write_lock(&resource_lock
);
541 conflict
= __insert_resource(parent
, new);
542 write_unlock(&resource_lock
);
547 * insert_resource - Inserts a resource in the resource tree
548 * @parent: parent of the new resource
549 * @new: new resource to insert
551 * Returns 0 on success, -EBUSY if the resource can't be inserted.
553 int insert_resource(struct resource
*parent
, struct resource
*new)
555 struct resource
*conflict
;
557 conflict
= insert_resource_conflict(parent
, new);
558 return conflict
? -EBUSY
: 0;
562 * insert_resource_expand_to_fit - Insert a resource into the resource tree
563 * @root: root resource descriptor
564 * @new: new resource to insert
566 * Insert a resource into the resource tree, possibly expanding it in order
567 * to make it encompass any conflicting resources.
569 void insert_resource_expand_to_fit(struct resource
*root
, struct resource
*new)
574 write_lock(&resource_lock
);
576 struct resource
*conflict
;
578 conflict
= __insert_resource(root
, new);
581 if (conflict
== root
)
584 /* Ok, expand resource to cover the conflict, then try again .. */
585 if (conflict
->start
< new->start
)
586 new->start
= conflict
->start
;
587 if (conflict
->end
> new->end
)
588 new->end
= conflict
->end
;
590 printk("Expanded resource %s due to conflict with %s\n", new->name
, conflict
->name
);
592 write_unlock(&resource_lock
);
596 * adjust_resource - modify a resource's start and size
597 * @res: resource to modify
598 * @start: new start value
601 * Given an existing resource, change its start and size to match the
602 * arguments. Returns 0 on success, -EBUSY if it can't fit.
603 * Existing children of the resource are assumed to be immutable.
605 int adjust_resource(struct resource
*res
, resource_size_t start
, resource_size_t size
)
607 struct resource
*tmp
, *parent
= res
->parent
;
608 resource_size_t end
= start
+ size
- 1;
611 write_lock(&resource_lock
);
613 if ((start
< parent
->start
) || (end
> parent
->end
))
616 for (tmp
= res
->child
; tmp
; tmp
= tmp
->sibling
) {
617 if ((tmp
->start
< start
) || (tmp
->end
> end
))
621 if (res
->sibling
&& (res
->sibling
->start
<= end
))
626 while (tmp
->sibling
!= res
)
628 if (start
<= tmp
->end
)
637 write_unlock(&resource_lock
);
641 static void __init
__reserve_region_with_split(struct resource
*root
,
642 resource_size_t start
, resource_size_t end
,
645 struct resource
*parent
= root
;
646 struct resource
*conflict
;
647 struct resource
*res
= kzalloc(sizeof(*res
), GFP_ATOMIC
);
655 res
->flags
= IORESOURCE_BUSY
;
657 conflict
= __request_resource(parent
, res
);
661 /* failed, split and try again */
664 /* conflict covered whole area */
665 if (conflict
->start
<= start
&& conflict
->end
>= end
)
668 if (conflict
->start
> start
)
669 __reserve_region_with_split(root
, start
, conflict
->start
-1, name
);
670 if (conflict
->end
< end
)
671 __reserve_region_with_split(root
, conflict
->end
+1, end
, name
);
674 void __init
reserve_region_with_split(struct resource
*root
,
675 resource_size_t start
, resource_size_t end
,
678 write_lock(&resource_lock
);
679 __reserve_region_with_split(root
, start
, end
, name
);
680 write_unlock(&resource_lock
);
683 EXPORT_SYMBOL(adjust_resource
);
686 * resource_alignment - calculate resource's alignment
687 * @res: resource pointer
689 * Returns alignment on success, 0 (invalid alignment) on failure.
691 resource_size_t
resource_alignment(struct resource
*res
)
693 switch (res
->flags
& (IORESOURCE_SIZEALIGN
| IORESOURCE_STARTALIGN
)) {
694 case IORESOURCE_SIZEALIGN
:
695 return resource_size(res
);
696 case IORESOURCE_STARTALIGN
:
704 * This is compatibility stuff for IO resources.
706 * Note how this, unlike the above, knows about
707 * the IO flag meanings (busy etc).
709 * request_region creates a new busy region.
711 * check_region returns non-zero if the area is already busy.
713 * release_region releases a matching busy region.
716 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait
);
719 * __request_region - create a new busy resource region
720 * @parent: parent resource descriptor
721 * @start: resource start address
722 * @n: resource region size
723 * @name: reserving caller's ID string
724 * @flags: IO resource flags
726 struct resource
* __request_region(struct resource
*parent
,
727 resource_size_t start
, resource_size_t n
,
728 const char *name
, int flags
)
730 DECLARE_WAITQUEUE(wait
, current
);
731 struct resource
*res
= kzalloc(sizeof(*res
), GFP_KERNEL
);
738 res
->end
= start
+ n
- 1;
739 res
->flags
= IORESOURCE_BUSY
;
742 write_lock(&resource_lock
);
745 struct resource
*conflict
;
747 conflict
= __request_resource(parent
, res
);
750 if (conflict
!= parent
) {
752 if (!(conflict
->flags
& IORESOURCE_BUSY
))
755 if (conflict
->flags
& flags
& IORESOURCE_MUXED
) {
756 add_wait_queue(&muxed_resource_wait
, &wait
);
757 write_unlock(&resource_lock
);
758 set_current_state(TASK_UNINTERRUPTIBLE
);
760 remove_wait_queue(&muxed_resource_wait
, &wait
);
761 write_lock(&resource_lock
);
764 /* Uhhuh, that didn't work out.. */
769 write_unlock(&resource_lock
);
772 EXPORT_SYMBOL(__request_region
);
775 * __check_region - check if a resource region is busy or free
776 * @parent: parent resource descriptor
777 * @start: resource start address
778 * @n: resource region size
780 * Returns 0 if the region is free at the moment it is checked,
781 * returns %-EBUSY if the region is busy.
784 * This function is deprecated because its use is racy.
785 * Even if it returns 0, a subsequent call to request_region()
786 * may fail because another driver etc. just allocated the region.
787 * Do NOT use it. It will be removed from the kernel.
789 int __check_region(struct resource
*parent
, resource_size_t start
,
792 struct resource
* res
;
794 res
= __request_region(parent
, start
, n
, "check-region", 0);
798 release_resource(res
);
802 EXPORT_SYMBOL(__check_region
);
805 * __release_region - release a previously reserved resource region
806 * @parent: parent resource descriptor
807 * @start: resource start address
808 * @n: resource region size
810 * The described resource region must match a currently busy region.
812 void __release_region(struct resource
*parent
, resource_size_t start
,
821 write_lock(&resource_lock
);
824 struct resource
*res
= *p
;
828 if (res
->start
<= start
&& res
->end
>= end
) {
829 if (!(res
->flags
& IORESOURCE_BUSY
)) {
833 if (res
->start
!= start
|| res
->end
!= end
)
836 write_unlock(&resource_lock
);
837 if (res
->flags
& IORESOURCE_MUXED
)
838 wake_up(&muxed_resource_wait
);
845 write_unlock(&resource_lock
);
847 printk(KERN_WARNING
"Trying to free nonexistent resource "
848 "<%016llx-%016llx>\n", (unsigned long long)start
,
849 (unsigned long long)end
);
851 EXPORT_SYMBOL(__release_region
);
854 * Managed region resource
856 struct region_devres
{
857 struct resource
*parent
;
858 resource_size_t start
;
862 static void devm_region_release(struct device
*dev
, void *res
)
864 struct region_devres
*this = res
;
866 __release_region(this->parent
, this->start
, this->n
);
869 static int devm_region_match(struct device
*dev
, void *res
, void *match_data
)
871 struct region_devres
*this = res
, *match
= match_data
;
873 return this->parent
== match
->parent
&&
874 this->start
== match
->start
&& this->n
== match
->n
;
877 struct resource
* __devm_request_region(struct device
*dev
,
878 struct resource
*parent
, resource_size_t start
,
879 resource_size_t n
, const char *name
)
881 struct region_devres
*dr
= NULL
;
882 struct resource
*res
;
884 dr
= devres_alloc(devm_region_release
, sizeof(struct region_devres
),
893 res
= __request_region(parent
, start
, n
, name
, 0);
901 EXPORT_SYMBOL(__devm_request_region
);
903 void __devm_release_region(struct device
*dev
, struct resource
*parent
,
904 resource_size_t start
, resource_size_t n
)
906 struct region_devres match_data
= { parent
, start
, n
};
908 __release_region(parent
, start
, n
);
909 WARN_ON(devres_destroy(dev
, devm_region_release
, devm_region_match
,
912 EXPORT_SYMBOL(__devm_release_region
);
915 * Called from init/main.c to reserve IO ports.
918 static int __init
reserve_setup(char *str
)
921 static struct resource reserve
[MAXRESERVE
];
924 unsigned int io_start
, io_num
;
927 if (get_option (&str
, &io_start
) != 2)
929 if (get_option (&str
, &io_num
) == 0)
931 if (x
< MAXRESERVE
) {
932 struct resource
*res
= reserve
+ x
;
933 res
->name
= "reserved";
934 res
->start
= io_start
;
935 res
->end
= io_start
+ io_num
- 1;
936 res
->flags
= IORESOURCE_BUSY
;
938 if (request_resource(res
->start
>= 0x10000 ? &iomem_resource
: &ioport_resource
, res
) == 0)
945 __setup("reserve=", reserve_setup
);
948 * Check if the requested addr and size spans more than any slot in the
949 * iomem resource tree.
951 int iomem_map_sanity_check(resource_size_t addr
, unsigned long size
)
953 struct resource
*p
= &iomem_resource
;
957 read_lock(&resource_lock
);
958 for (p
= p
->child
; p
; p
= r_next(NULL
, p
, &l
)) {
960 * We can probably skip the resources without
961 * IORESOURCE_IO attribute?
963 if (p
->start
>= addr
+ size
)
967 if (PFN_DOWN(p
->start
) <= PFN_DOWN(addr
) &&
968 PFN_DOWN(p
->end
) >= PFN_DOWN(addr
+ size
- 1))
971 * if a resource is "BUSY", it's not a hardware resource
972 * but a driver mapping of such a resource; we don't want
973 * to warn for those; some drivers legitimately map only
974 * partial hardware resources. (example: vesafb)
976 if (p
->flags
& IORESOURCE_BUSY
)
979 printk(KERN_WARNING
"resource map sanity check conflict: "
980 "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
981 (unsigned long long)addr
,
982 (unsigned long long)(addr
+ size
- 1),
983 (unsigned long long)p
->start
,
984 (unsigned long long)p
->end
,
989 read_unlock(&resource_lock
);
994 #ifdef CONFIG_STRICT_DEVMEM
995 static int strict_iomem_checks
= 1;
997 static int strict_iomem_checks
;
1001 * check if an address is reserved in the iomem resource tree
1002 * returns 1 if reserved, 0 if not reserved.
1004 int iomem_is_exclusive(u64 addr
)
1006 struct resource
*p
= &iomem_resource
;
1009 int size
= PAGE_SIZE
;
1011 if (!strict_iomem_checks
)
1014 addr
= addr
& PAGE_MASK
;
1016 read_lock(&resource_lock
);
1017 for (p
= p
->child
; p
; p
= r_next(NULL
, p
, &l
)) {
1019 * We can probably skip the resources without
1020 * IORESOURCE_IO attribute?
1022 if (p
->start
>= addr
+ size
)
1026 if (p
->flags
& IORESOURCE_BUSY
&&
1027 p
->flags
& IORESOURCE_EXCLUSIVE
) {
1032 read_unlock(&resource_lock
);
1037 static int __init
strict_iomem(char *str
)
1039 if (strstr(str
, "relaxed"))
1040 strict_iomem_checks
= 0;
1041 if (strstr(str
, "strict"))
1042 strict_iomem_checks
= 1;
1046 __setup("iomem=", strict_iomem
);